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As filed with the Securities and Exchange Commission on December 1, 2003

Registration No. 333-110564

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 20549

Amendment No. 1

to

Form S-1

REGISTRATION STATEMENT

UNDER

THE SECURITIES ACT OF 1933

Infinity Property and Casualty Corporation

(Exact Name of Registrant as Specified in Its Charter)

2204 Lakeshore Drive

Birmingham, Alabama 35209

(205) 870-4000

(Address, Including Zip Code, and Telephone Number, Including Area Code, of Registrant’s Principal Executive Offices)

Samuel J. Simon, Esq.

Senior Vice President, General Counsel and Secretary

Infinity Property and Casualty Corporation

2204 Lakeshore Drive

Birmingham, Alabama 35209

Telephone: (205) 870-4000

Facsimile: (205) 803-8585

(Name, Address, Including Zip Code, Telephone and Facsimile Numbers, Including Area Code, of Agent For Service)

With copies to:

Approximate date of commencement of proposed sale to the public: As soon as practicable after the effective date of this Registration Statement.

If any of the securities being registered on this form are to be offered on a delayed or continuous basis pursuant to Rule 415 under the Securities Act of 1933, check the following box.    ¨

If this form is filed to register additional securities for an offering pursuant to Rule 462(b) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(c) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    ¨

If this Form is a post-effective amendment filed pursuant to Rule 462(d) under the Securities Act, check the following box and list the Securities Act registration statement number of the earlier effective registration statement for the same offering.    ¨

If delivery of the prospectus is expected to be made pursuant to Rule 434, please check the following box.    ¨

The Registrant hereby amends this Registration Statement on such date or dates as may be necessary to delay its effective date until the Registrant shall file a further amendment which specifically states that this Registration Statement shall thereafter become effective in accordance with Section 8(a) of the Securities Act of 1933, or until the Registration Statement shall become effective on such date as the Commission, acting pursuant to said Section 8(a), may determine.

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The information in this prospectus is not complete and may be changed. This prospectus is not an offer to sell these securities and is not soliciting an offer to buy these securities in any state where the offer or sale is not permitted.

SUBJECT TO COMPLETION, DATED DECEMBER 1, 2003

PROSPECTUS

7,850,465 Common Shares

Infinity Property and Casualty Corporation

Common Stock

A wholly-owned subsidiary of American Financial Group, Inc. is selling all of the shares of common stock in this offering other than the shares subject to the over-allotment option described below. Infinity will not receive any of the proceeds from the sale of the shares by the selling shareholder. Our common stock is quoted on the Nasdaq National Market under the symbol “IPCC.” On November 25, 2003, the last quoted price of the shares of common stock as reported on the Nasdaq National Market was $34.00 per share.

Investing in our common stock involves risks that are described in the “ Risk Factors” section beginning on page 10 of this prospectus.

The underwriters may also purchase up to an additional 1,177,569 shares of common stock from us at the public offering price, less the underwriting discount, within 30 days from the date of this prospectus to cover over-allotments. If the underwriters exercise that option in full, the total public offering price, underwriting discount and proceeds to us would be $     , $     , and $     , respectively.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The shares of common stock will be ready for delivery on or about                     , 2003.

Banc of America Securities LLC

Bear, Stearns & Co. Inc.

Morgan Keegan & Company, Inc.

The date of this prospectus is                    , 2003.

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You should rely only on the information contained in this document or to which we have referred you. We have not authorized anyone to provide you with information that is different. This document may only be used where it is legal to sell these securities. The information in this document may only be accurate on the date of this document.

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PROSPECTUS SUMMARY

This summary highlights information about Infinity Property and Casualty Corporation and the offering. Because this is a summary, it may not contain all the information you should consider before investing in our common stock. You should carefully read this entire prospectus.

References in this prospectus to “Infinity,” “we,” “us” and “our”, unless the context requires otherwise, refer to Infinity Property and Casualty Corporation and its combined operations, including the Assumed Agency Business. Unless otherwise noted in this prospectus, we assume that the underwriters will not exercise their over-allotment option. Unless otherwise indicated, all financial information in this prospectus is presented on a pro forma basis for periods prior to December 31, 2002 (see “Our Formation and Separation from AFG” and “Unaudited Pro Forma Financial Information”). In this prospectus, all share and per share data assumes that the stock split we declared in January 2003 had already occurred. Unless otherwise indicated, insurance industry data and our market share or ranking in the industry were derived from data compiled by A.M. Best Company Inc.

Infinity

What We Do

We are a national provider of personal automobile insurance with an emphasis on nonstandard auto insurance. Nonstandard auto insurance provides coverage to drivers who, due to their driving record, age or vehicle type, represent higher than normal risks and pay higher rates for comparable coverage. We also write standard and preferred personal auto insurance, nonstandard commercial auto insurance and complementary personal lines insurance products.

Our products are offered primarily through a network of approximately 14,000 independent agencies and strategic partnerships. Based on data published by A.M. Best, we believe we are the second largest provider of nonstandard auto coverage through independent agents in the United States, behind only The Progressive Corporation. While licensed to write insurance in every state, we focus on 15 states which we believe provide the greatest opportunity for profitable growth.

In 2002, we generated, on a pro forma basis, $988.9 million in gross premiums written, $687.3 million in net premiums written and had net earnings of $36.3 million. For the nine months ended September 30, 2003, we generated $734.8 million in gross premiums written, $622.8 million in net premiums written and had net earnings of $38.8 million. For the year ended December 31, 2002 and the nine months ended September 30, 2003, approximately 95% of our business was personal auto and the remaining 5% was homeowners, umbrella liability, boat owners and nonstandard commercial auto coverages. While there is no precise, industry-recognized definition of nonstandard auto insurance, we estimate that, for the year ended December 31, 2002 and the nine months ended September 30, 2003, approximately four-fifths of our personal auto business was nonstandard coverage. At September 30, 2003, we had total assets of $2.0 billion, total liabilities of $1.5 billion and shareholders’ equity of $442 million.

The following table compares our statutory combined ratio in past years with those of the personal lines insurance industry as a whole. See “Business — Our Strengths” for a description of how the combined ratio is calculated, the use of the combined ratio as a measure of underwriting profitability and the source of the industry combined ratios presented.

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Our Strengths

We believe that we are well positioned to compete in today’s market through various strengths that should enable us to build upon our history of favorable underwriting results. These strengths include:

Our Strategy

Our goal is to maximize shareholder value by focusing on underwriting profitability and long-term return on equity. We pursue this goal through a strategy of:

Certain Risks We Face

Our ability to capitalize on our strengths and implement our strategy entails risks. For example, we have a limited operating history as an independent public company. Further, the process of consolidating the operations of our insurance subsidiaries poses managerial, strategic and technological challenges. Adverse developments in the market for personal automobile insurance, or the personal automobile insurance industry in general, could cause our results of operations to suffer. Our reliance on the independent agency market makes us vulnerable to a reduction in the amount of business written by independent agents, and if we are not able to attract and retain independent agents, our revenues could be negatively affected. For further discussion of these and other risks we face, see “Risk Factors”.

Our principal executive offices are located at 2204 Lakeshore Drive, Birmingham, Alabama, 35209. Our telephone number is (205) 870-4000.

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The Offering

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Our Formation and Separation from AFG

Infinity was formed in September 2002 as an indirect wholly-owned subsidiary of American Financial Group, Inc. to acquire and conduct, as a separate public company, AFG’s personal lines insurance business written through independent agents. Prior to the initial public offering of common stock, AFG transferred to Infinity all of the issued and outstanding capital stock of the following personal auto insurance subsidiaries, including their respective subsidiaries, involved primarily in the issuance of nonstandard auto policies: Atlanta Casualty Company, Leader Insurance Company, Infinity Insurance Company and Windsor Insurance Company. We refer to these subsidiaries as the NSA Group. In this prospectus, we refer to our operations and financial results before January 1, 2003 as the operations and financial results of either Infinity or the NSA Group. In exchange for the NSA Group, AFG received all of the issued and outstanding shares of Infinity common stock and a note payable in the amount of $55 million.

In addition, as of January 1, 2003, AFG’s principal property and casualty insurance subsidiary, Great American Insurance Company (“Great American”), transferred to us its personal insurance business written through independent agents. This is primarily auto insurance for standard and preferred drivers, but also includes other personal lines. Because this business is not a separate legal entity, the transfer was effected through a reinsurance agreement under which we assumed the inforce business, service the policyholders and handle the claims. Great American, in turn, transferred to us assets (primarily investment securities) with a market value of $125.3 million, which was approximately equal to the net liabilities related to the inforce business, less

$5 million. We refer to this business as the Assumed Agency Business.

We completed the initial public offering of our common stock in February 2003. In the initial public offering, AFG sold 12.5 million shares of our common stock held by it. We received no proceeds from the initial public offering. AFG is selling its remaining shares in this offering.

The financial assets transferred to us from Great American in connection with our acquisition of Great American’s personal insurance business written through independent agents include primarily investment securities which are described in more detail in Note 1 to the Unaudited Pro Forma Financial Information. Other financial assets (primarily agents’ balances and deferred policy acquisition costs) and financial liabilities (primarily loss reserves and unearned premiums) transferred are described more fully in the Statement of Assets (excluding investments) and Liabilities to be Transferred for this business which begin on page F-18 of this Prospectus. In addition to the transfer of financial assets and liabilities, we received the operational processes, including policy renewal rights, and employees necessary to conduct the normal operations of this business following the date of transfer. Accordingly, the transfer represented the acquisition of a “business” under generally accepted accounting principles. Since the transfer was made while Infinity was an AFG subsidiary, the assets and liabilities transferred were recorded at AFG’s historical cost.

The companies and business comprising Infinity represented approximately 31% of AFG’s entire property and casualty group and approximately 83% of AFG’s Personal segment based on earned premiums in 2002. AFG’s property and casualty group was engaged primarily in specialty and private passenger automobile insurance businesses. The Specialty group includes a highly diversified group of specialty business units. Some of the more significant areas are inland and ocean marine, California workers’ compensation, agricultural-related coverages, executive and professional liability, fidelity and surety bonds, collateral protection, and umbrella and excess coverages. The Personal group wrote nonstandard and preferred/standard private passenger auto and other personal insurance coverage. AFG’s annuity and life business markets primarily retirement products as well as life and supplemental health insurance. AFG’s businesses operate throughout the United States. In 2002, 2001 and 2000, AFG derived less than 2% of its revenues from the sale of life and supplemental health products in Puerto Rico and less than 1% of its revenues from the sale of property and casualty insurance in Mexico, Canada, Puerto Rico, Europe and Asia.

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The following table (in millions) shows AFG’s revenues by significant business segment for the three years preceding our initial public offering of common stock.

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Summary Historical Financial Data

We derived the summary data as of and for each of the three years ended December 31, 2002, from financial statements audited by Ernst & Young LLP. We derived the summary data as of and for the nine months ended September 30, 2003 and 2002, from unaudited financial statements which include all adjustments, consisting of normal recurring accruals, that management considers necessary for a fair presentation of the financial position and results of operations for those periods. Results for the interim periods are not necessarily indicative of results to be expected for the entire year. The Infinity financial data set forth below for all periods prior to December 31, 2002 is the financial data of the NSA Group. The Infinity financial data for the nine months ended September 30, 2003 include the results of the Assumed Agency Business. You should read this summary in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the financial statements and related notes appearing elsewhere in this prospectus.

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RISK FACTORS

An investment in the common stock involves a number of risks. You should carefully consider the following information, together with the other information contained in this prospectus, before investing in the common stock.

We have a limited operating history as a stand-alone entity.

We became an independent public company in February 2003. Prior to that time, our insurance subsidiaries relied on AFG for assistance with respect to financial, administrative, managerial and other matters. While we have developed our own credit and banking relationships and perform our own financial and investor relations functions, continuing to develop the infrastructure necessary to operate as an independent public company has required and will continue to require a substantial amount of time and resources.

Our ongoing consolidation of the operations of our insurance subsidiaries may not be successful.

We are combining the operations of several insurance companies that have operated previously as independent business units. The process of consolidating the operations of our insurance subsidiaries poses managerial, strategic and technological challenges for us as an independent company, particularly with respect to the integration of historically separate information systems to a single system. The prospective costs and benefits of the consolidation may not result in equivalent or greater operating efficiencies and savings than those that have already been achieved. Such consolidation may negatively impact our revenues.

Because we are primarily a personal automobile insurer, our business may be adversely affected by conditions in that business.

Approximately 95% of our gross written premiums for the year ended December 31, 2002 and the nine months ended September 30, 2003 were generated from personal automobile insurance policies. Adverse developments in the market for personal automobile insurance, or the personal automobile insurance industry in general, could cause our results of operations to suffer. Our industry is exposed to the risks of severe weather conditions, such as rainstorms, snowstorms, hail and ice storms, hurricanes, tornadoes, earthquakes and, to a lesser degree, explosions, terrorist attacks and riots. The automobile insurance business is also affected by cost trends that impact profitability. Factors which negatively affect cost trends include inflation in automobile repair costs, automobile parts costs, used car prices and medical care. Increased litigation of claims may also negatively affect loss costs.

Our results may fluctuate as a result of cyclical changes in the personal auto insurance industry.

The personal auto insurance industry historically is cyclical in nature. The industry has been characterized by periods of price competition and excess capacity followed by periods of high premium rates and shortages of underwriting capacity. These fluctuations in the business cycle would be likely to negatively impact our revenues.

Intense competition could adversely affect our profitability.

The personal automobile insurance business is highly competitive and, except for regulatory considerations, there are relatively few barriers to entry. We compete with both large national writers and smaller regional companies. Some of our competitors have more capital and greater resources than we have, and may offer a broader range of products and lower prices than we offer. Some of our competitors that are direct writers, as opposed to agency writers as we are, may have certain competitive advantages, including increased name recognition, direct relationships with policyholders rather than with independent agents and, potentially, lower cost structures.

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We are vulnerable to a reduction in the amount of business written by independent agents.

Our reliance on the independent agency market makes us vulnerable to a reduction in the amount of business written by independent agents. Many of our competitors, like us, rely significantly on the independent agency market. Approximately two-thirds of all personal automobile insurance is sold direct or through captive agents (agents employed by the company or selling only one company’s products) and approximately one-third is sold by independent agents. A material reduction in the amount of business independent agents sell would negatively impact our revenues.

If we are not able to attract and retain independent agents, our revenues could be negatively affected.

We must compete with other insurance carriers for independent agents’ business. Some of our competitors offer a larger variety of products, lower prices for insurance coverage or higher commissions. While we believe that the products, pricing, commissions and services we offer agents are competitive, we may not be able to continue to attract and retain independent agents to sell our insurance products, in which case, our revenues could be negatively affected.

We are subject to comprehensive regulation, and our ability to earn profits may be restricted by these regulations.

We are subject to comprehensive regulation by government agencies in the states where our insurance company subsidiaries are domiciled (California, Indiana, Ohio, Oklahoma and Texas) and where these subsidiaries issue policies and handle claims. We must comply with regulations involving:

In addition, state insurance department examiners perform periodic financial and market conduct examinations of insurance companies. Such regulation is generally intended for the protection of policyholders rather than securityholders.

Regulation may become more extensive in the future.

Existing insurance-related laws and regulations may become more restrictive in the future, and new restrictive laws may be enacted. New or more restrictive regulation in the future could make it more expensive for us to conduct our business, restrict the premiums we are able to charge or otherwise change the way we do business. See “Business — Regulatory Environment.”

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Our insurance subsidiaries are subject to minimum capital and surplus requirements. Our failure to meet these requirements could subject us to regulatory action.

Our insurance subsidiaries are subject to minimum capital and surplus requirements imposed under the laws of California, Indiana, Ohio, Oklahoma and Texas. Any failure by one of our insurance subsidiaries to meet the minimum capital and surplus requirements imposed by applicable state law will subject it to corrective action, including requiring the adoption of a comprehensive financial plan, examination and the issuance of a corrective order by the applicable state insurance department, revocation of its license to sell insurance products or placing the subsidiary under state regulatory control. Any new minimum capital and surplus requirements adopted in the future may require us to increase our capital and surplus levels, which we may be unable to do. As of September 30, 2003, each of our insurance company subsidiaries had capital and surplus substantially in excess of the currently required amounts.

As a holding company, we are dependent on the results of operations of our insurance company subsidiaries to meet our obligations and pay future dividends.

We are a holding company and a legal entity separate and distinct from our insurance company subsidiaries. As a holding company without significant operations of our own, our principal sources of funds are dividends and other distributions from our insurance company subsidiaries. State insurance laws limit the ability of our insurance companies to pay dividends and require our insurance companies to maintain specified levels of statutory capital and surplus. In addition, for competitive reasons, our insurance companies need to maintain financial strength ratings which requires us to sustain capital levels in those subsidiaries. These restrictions affect the ability of our insurance company subsidiaries to pay dividends and use their capital in other ways. Our rights to participate in any distribution of assets of our insurance company subsidiaries are subject to prior claims of policyholders and creditors (except to the extent that our rights, if any, as a creditor are recognized). Also, the covenants in our term loan require us to maintain minimum levels of capital and surplus which may limit the ability of our insurance company subsidiaries to pay dividends to us. Consequently, our ability to pay debts, expenses and cash dividends to our shareholders may be limited. See “Management’s Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources — Sources of Funds” and “Business — Regulatory Environment.”

Our failure to maintain a commercially acceptable financial strength rating would significantly and negatively affect our ability to implement our business strategy successfully.

Financial strength ratings are an important factor in establishing the competitive position of insurance companies and may be expected to have an effect on an insurance company’s sales. A.M. Best has currently assigned our insurance company subsidiaries a group rating of “A (Excellent)”. According to A.M. Best, “A” ratings are assigned to insurers which have, on balance, excellent balance sheet strength, operating performance and business profile when compared to the standards established by A.M. Best and, in A.M. Best’s opinion, have a strong ability to meet their ongoing obligations to policyholders. A.M. Best bases its ratings on factors that concern policyholders and not upon factors concerning investor protection. Such ratings are subject to change and are not recommendations to buy, sell or hold securities. There can be no assurance that our rating or future changes to our rating will not affect our competitive position. See “Business — Ratings.”

We are parties to litigation which, if decided adversely to us, could impact our financial results.

We are named as a defendant in a number of lawsuits, including several class actions. These lawsuits are described more fully in “Business — Legal Proceedings”. Litigation, by its very nature, is unpredictable and the outcome of these cases is uncertain. Further, the precise nature of the relief that may be sought or granted in any lawsuits is uncertain and may, if these lawsuits are determined adversely to us, negatively impact our earnings. See “Business — Legal Proceedings.”

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New claim and coverage issues are continually emerging, and these new issues could negatively impact our revenues or our method of doing business.

As automobile insurance industry practices and regulatory, judicial, and consumer conditions change, unexpected and unintended issues related to claims and coverage may emerge. The issues can have a negative effect on our business by either extending coverage beyond our underwriting intent or by increasing the size of claims. Recent examples of emerging claims and coverage issues include:

The effects of these and other unforeseen emerging claim and coverage issues could negatively impact our revenues or our methods of doing business. See “Business — Legal Proceedings.”

Our reserves may be inadequate, which could significantly affect our financial results.

We record reserve liabilities for the estimated payment of losses and loss adjustment expenses for both reported and unreported claims. Due to the inherent uncertainty of estimating reserves, it has been necessary in the past, and may continue to be necessary in the future, to revise estimated liabilities as reflected in our reserves for claims and related expenses. To the extent that reserves are inadequate and are strengthened, the amount of such increase is treated as a charge to earnings in the period in which the deficiency is recognized. The historic development of reserves for losses and loss adjustment expense may not necessarily reflect future trends in the development of these amounts. Accordingly, it is not appropriate to extrapolate redundancies or deficiencies based on historical information.

We are dependent on key executives.

Our success will depend in part upon the continued service of our Chief Executive Officer and President, James R. Gober, our Executive Vice President, John R. Miner, our Senior Vice President and General Counsel, Samuel J. Simon, our Senior Vice President and Chief Financial Officer, Roger Smith and our Senior Vice President, Joseph A. Pietrangelo. We have employment or severance agreements with two of our executives which we describe in “Management —Agreements with Executives”. We do not have key person insurance on the lives of any of these individuals. Our success will also depend on our ability to attract and retain additional executives and personnel. The loss of key personnel could cause disruption in our business. As we grow, we will need to recruit and retain additional qualified personnel, and we may not be able to do so.

Adverse securities market conditions can have significant and negative effects on our investment portfolio.

Our results of operations depend in part on the performance of our invested assets. As of September 30, 2003, 98% of our investment portfolio was invested in fixed maturity securities and 2% in equity securities. Certain risks are inherent in connection with fixed maturity securities including loss upon default and price volatility in reaction to changes in interest rates and general market factors. An increase in interest rates lowers prices on fixed maturity securities, and any sales we make during a period of increasing interest rates may result in losses. Conversely, investment income earned from future investments in fixed maturity securities will decrease if interest rates decrease.

Our results may be adversely affected by conditions in the states where our business is concentrated.

For the year ended December 31, 2002 and the nine months ended September 30, 2003, we generated approximately 80% and 87%, respectively, of our gross written premiums in our top 15 states. California,

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our largest market, generated approximately 34% and 46%, respectively, of our gross written premiums in 2002 and the nine months ended September 30, 2003. Our revenues and profitability are therefore subject to prevailing regulatory, legal, economic, demographic, competitive and other conditions in these states. Changes in any of these conditions could make it less attractive for us to do business in those states. Adverse regulatory developments in any of these states, which could include, among others, reductions in the rates permitted to be charged, inadequate rate increases, an inability to reduce the amount of insurance we write in those states, or more fundamental changes in the design or implementation of the automobile insurance regulatory framework, could negatively affect our premium revenue or make it more expensive or less profitable for us to conduct our business.

We are dependent on certain contractual arrangements with AFG, and we may be unable to replace these arrangements, upon their expiration, with similar or more favorable arrangements.

In connection with the initial public offering of common stock, we entered into a formation and separation agreement, a registration rights agreement, a noncompetition agreement, an investment advisory agreement, a tax allocation indemnification agreement, a services agreement and other arrangements and agreements with AFG and certain of its affiliates. See “Certain Arrangements and Relationships Between Our Company and AFG.” We negotiated the terms of these agreements with AFG. Our board of directors approved the terms of these agreements, but the agreements were not reviewed or approved by the independent directors who joined our board upon completion of the initial public offering of our common stock. Several of these agreements govern our relationship with AFG and its affiliates with respect to various intercompany services which AFG and its affiliates provide us. After the expiration of these agreements, we may not be able to replace these services and arrangements in a timely manner or on terms and conditions, including cost, as favorable as those we have with AFG.

Certain provisions contained in our organizational documents and the insurance laws of various states could impede an attempt to replace or remove our management or prevent the sale of our company, which could diminish the value of our common stock.

Our Articles of Incorporation and Regulations and the insurance laws of various states contain provisions that could impede an attempt to replace or remove our management or prevent the sale of our company that, in either case, shareholders might not consider to be in their best interests. For instance, these provisions may prevent shareholders from receiving the benefit of any premium over the market price of our common stock offered by a bidder in a potential takeover. In addition, the existence of these provisions may adversely affect the prevailing market price of our common stock if they are viewed as discouraging takeover attempts in the future. See “Business — Regulatory Environment” and “Description of Capital Stock.”

CAUTIONARY STATEMENT CONCERNING FORWARD LOOKING STATEMENTS

Some of the statements under “Summary,” “Risk Factors,” “Management’s Discussion and Analysis of Financial Condition and Results of Operations,” “Business” and elsewhere in this prospectus may include forward-looking statements which reflect our current views with respect to future events and financial performance. These statements include forward-looking statements both with respect to us and the insurance industry. Statements which include the words “believes”, “expects”, “may”, “will”, “should”, “seeks”, “intends”, “plans”, “estimates”, “anticipates” or the negative version of those words or other comparable terminology and similar statements of a future or forward-looking nature identify forward-looking statements.

These are forward-looking statements within the meaning of Section 27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act of 1934. Examples of such forward-looking statements include statements relating to: expectations concerning market and other conditions, future premiums, revenues, earnings and investment activities, expected losses, rate increases, improved loss experience and expected expense savings

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resulting from consolidation of the operations of our subsidiaries. Actual results could differ materially from those we expect depending on certain risks and uncertainties including but not limited to:

All forward-looking statements address matters that involve risks and uncertainties. Accordingly, there are or will be important factors that could cause actual results to differ materially from those indicated in these statements. We believe that these factors include but are not limited to those described under “Risk Factors” above. We undertake no obligation to publicly update or review any forward-looking statement, whether as a result of new information, future developments or otherwise.

USE OF PROCEEDS

We will receive no proceeds from the sale of common stock by the selling shareholder. Fifty percent of any proceeds that we receive from the exercise of the underwriters’ over-allotment option will be used to repay debt as required under provisions of the term loan we secured in July 2003. The remaining proceeds will be used for general corporate purposes. Our term loan matures on June 30, 2010 and currently bears interest at 3.6%. Proceeds of $110 million from the term loan were contributed to our insurance subsidiaries to support future growth of their business and reduce our reliance on reinsurance, and the remaining proceeds were used to repay a $55 million promissory note issued to AFG in connection with our formation and for general corporate purposes.

CAPITALIZATION

The following table shows our capitalization at September 30, 2003. This information should be read in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the financial statements and related notes appearing elsewhere in this prospectus.

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PRICE RANGE FOR COMMON STOCK AND DIVIDENDS

Our common stock began trading on February 18, 2003 on the Nasdaq National Market under the symbol “IPCC.” The following table sets forth, for the periods indicated, the high and low sales prices per share of common stock as reported on the Nasdaq National Market and the dividends paid per share of common stock during such period.

On November 25, 2003, the last quoted price per share of our common stock on the Nasdaq National Market was $34.00. As of September 30, 2003, we had 10 shareholders of record and approximately 116 beneficial holders of our common stock.

DIVIDEND POLICY

Our board of directors currently intends to declare a dividend on our common stock of $0.22 per share annually. In 2003, our board of directors declared dividends of $0.055 per share of common stock which were paid on each of May 25, August 28 and November 14, 2003. The declaration and payment of dividends is subject to the discretion of our board of directors, and will depend on, among other things, our financial condition, results of operations, capital and cash requirements, future prospects, regulatory and contractual restrictions on the payment of dividends by our subsidiaries, and other factors deemed relevant by the board. For a discussion of our cash resources and needs, see “Management’s Discussion and Analysis of Financial Condition and Results of Operations — Liquidity and Capital Resources.”

We are a holding company and a legal entity separate and distinct from our insurance company subsidiaries. As a holding company without significant operations of our own, our principal sources of funds are dividends and other distributions from our insurance company subsidiaries. Our ability to receive dividends from subsidiaries is subject to limits under applicable state insurance laws. See “Business — Regulatory Environment.”

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SELECTED HISTORICAL FINANCIAL DATA

The following tables summarize certain historical financial data of Infinity and of the Assumed Agency Business. We derived the data as of and for each of the four years ended December 31, 2002, from financial statements audited by Ernst & Young LLP. We derived the data as of and for the year ended December 31, 1998, and the nine months ended September 30, 2003 and 2002, from unaudited financial statements which include all adjustments, consisting of normal recurring accruals, that management considers necessary for a fair presentation of the financial position and results of operations for those periods. Results for the interim periods are not necessarily indicative of results to be expected for the entire year. The Infinity financial data set forth below for all periods prior to December 31, 2002 is the financial data of the NSA Group. The Infinity financial data for the nine months ended September 30, 2003 include the results of the Assumed Agency Business. You should read this data in conjunction with “Management’s Discussion and Analysis of Financial Condition and Results of Operations” and the financial statements and related notes appearing elsewhere in this prospectus.

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