SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES

The significant accounting policies used by Enterprise Financial Services Corp (the "Company" or "Enterprise") in the preparation of the condensed consolidated financial statements are summarized below:

Business and Consolidation

Enterprise is a financial holding company that provides a full range of banking and wealth management services to individuals and corporate customers located in the St. Louis, Kansas City, and Phoenix metropolitan markets through its banking subsidiary, Enterprise Bank & Trust (the "Bank").

Operating results for the three and nine months ended September 30, 2018 are not necessarily indicative of the results that may be expected for any other interim period or for the year ending December 31, 2018. For further information, refer to the consolidated financial statements and footnotes thereto included in the Company's Annual Report on Form 10-K for the year ended December 31, 2017, as filed with the Securities and Exchange Commission.

Basis of Financial Statement Presentation

The accompanying unaudited condensed consolidated financial statements of the Company and its subsidiaries have been prepared in accordance with the accounting principles generally accepted in the United States of America ("U.S. GAAP") for interim financial information and with the instructions to Form 10-Q and Rule 10-01 of Regulation S-X. The condensed consolidated financial statements include the accounts of the Company and its subsidiaries, all of which are wholly owned. All intercompany accounts and transactions have been eliminated.

During the first quarter of 2018, the Company adopted Accounting Standards Update ("ASU") 2016-01, "Financial Instruments-Overall (Subtopic 825-10): Recognition and Measurement of Financial Assets and Financial Liabilities." ASU 2016-01 requires equity investments to be measured at fair value through earnings, and eliminates the available-for-sale classification for equity securities with readily determinable fair values. The guidance also provides an alternative to measure equity securities without readily determinable fair values at cost less impairment (if any), plus or minus observable price changes from an identical or similar investment of the same issuer (the “measurement alternative”). The Company elected the measurement alternative for its qualifying equity securities. The adoption of this update resulted in an insignificant increase to retained earnings which was reclassified from accumulated other comprehensive income.

In addition, the Company early adopted ASU 2017-12, "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities" during the first quarter of 2018. The objective of ASU 2017-12 is to improve the financial reporting of hedging relationships by better aligning an entity's risk management activity with the economic objectives in undertaking those activities. The adoption of this update did not have a material effect on the Company's consolidated financial statements.

The Company also early adopted ASU 2018-02, "Income Statement - Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" during the first quarter of 2018. The ASU allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act of 2017, which among other things, reduced the maximum federal corporate tax rate from 35% to 21%. The adoption of this update resulted in an increase to retained earnings of $0.8 million which was reclassified from accumulated other comprehensive income.

In the opinion of management, the consolidated financial statements contain all adjustments (consisting of normal recurring accruals) considered necessary for the fair presentation of the statements of financial position, results of operations, and cash flow for the interim periods.

Revenue

The Company adopted the accounting standard regarding revenue recognition in the first quarter of 2018 using the modified retrospective approach. The Company's revenues are primarily composed of interest income on financial instruments, including investment securities, which are excluded from the scope of the new guidance. Certain other noninterest income from loans, investment securities and derivative financial instruments is also excluded from this guidance. Service charges on deposit accounts, wealth management revenue, card services revenue, and gain on sale of other real estate are within the scope of the guidance; however, there were no accounting policy changes as the Company's policies were consistent with the new guidance. Other noninterest income sources of revenue are considered immaterial. Implementation of this guidance did not change current business practices or have any changes to the Company's consolidated financial statements.

Descriptions of our revenue-generating activities within the scope of this guidance, which are presented in our income statement as components of noninterest income are as follows:


•	Service charges on deposit accounts - represents fees generated from a variety of deposit products and services provided to customers under a day-to-day contract. These fees are recognized on a daily or monthly basis.


•	Wealth management revenue - represents monthly fees earned from directing, holding, and managing customers’ assets. Revenue is recognized over regular intervals, either monthly or quarterly.


•	Card services revenue - represents revenue earned from merchant, debit and credit cards as incurred and includes a contra revenue account for rebates.


•	Gain on sale of other real estate - represents income recognized at delivery of control of a property at the time of a real estate closing.

Income Taxes

The SEC staff issued SAB 118, which provides guidance on accounting for the tax effects of the Tax Cuts and Jobs Act of 2017 (“Tax Act”). SAB 118 provides a measurement period that should not extend beyond one year from the Tax Act enactment date for companies to complete the accounting under ASC 740. In accordance with SAB 118, a company must reflect the income tax effects of those aspects of the Act for which the accounting under ASC 740 is complete. To the extent a company’s accounting for certain income tax effects of the Tax Act is incomplete but it is able to determine a reasonable estimate, it must record a provisional estimate in the financial statements. If a company cannot determine a provisional estimate to be included in the financial statements, it should continue to apply ASC 740 on the basis of the provisions of the tax laws that were in effect immediately before the enactment of the Tax Act. The Company has recorded amounts for the effects of the Tax Act using reasonable estimates based on currently available information and its interpretations thereof. This accounting may change due to, among other things, changes in interpretations the Company has made and the issuance of new tax or accounting guidance.