CoastalSouth Bancshares, Inc. Revenue Disclosure

NOTE 18 — REVENUE RECOGNITION

Accounting Standards Codification (“ASC”) 606, Revenue from Contracts with Customers (“ASC 606”), establishes principles for reporting information about the nature, amount, timing and uncertainty of revenue and cash flows arising from the entity’s contracts to provide goods or services to customers. The core principle requires an entity to recognize revenue to depict the transfer of goods or services to customers in an amount that reflects the consideration that it expects to be entitled to receive in exchange for those goods or services recognized as performance obligations are satisfied.

The Company’s sources of revenue are generated from both interest and noninterest revenue streams. The majority of our revenue-generating transactions are not subject to ASC 606. Revenue streams generated by fees and interest from financial instruments, investments, and transfers and servicing of these assets are excluded from this disclosure.

The Company has certain revenue streams within the scope of ASC 606 contained within noninterest income. The Company’s contracts with customers generally do not contain terms that require significant judgment to determine the amount of revenue to recognize.

Gain on sale of government guaranteed loans — The Company records a gain from the sale of government guaranteed loans to third parties at the time the transfer is complete. The gain on sale is recognized as a result of the recognition of mortgage servicing rights and premiums paid by the buyer for the purchase of the loan.

Bank-owned life insurance — The Company’s income from bank-owned life insurance primarily represents changes in the cash surrender value of such life insurance policies held on certain key employees, for which the Company is the owner and beneficiary. Revenue is recognized in each period based on the change in cash surrender value during the period.

Income from mortgage originations — The Company earns mortgage production income which is comprised primarily of activity related to the sale of consumer mortgage loans as well as loan origination fees such as closing charges, document review fees, application fees, other loan origination fees, and loan processing fees.

Interchange income and card fees — The Company earns interchange fees from debit cardholder transactions conducted through a payment network. Interchange fees from cardholder transactions represent a percentage of the underlying transaction value and are earned daily.

Service charges on deposit accounts — The Company earns fees from its deposit customers for transaction-based, account maintenance, and overdraft services. Transaction-based fees, which include services such as ATM use fees and stop payment charges, are recognized at the time the transaction is executed as that is the point in time the Company fulfills the customer’s request. Account maintenance fees, which relate primarily to monthly maintenance, are earned over the course of a month, representing the period over which the Company satisfies the performance obligation. Overdraft fees are recognized at the point in time that the overdraft occurs. Service charges are withdrawn from the customer’s account balance.

Losses on sale of available-for-sale securities — The Company recognizes realized gains or losses from the sale of its available-for-sale securities at the trade date and recognizes periodic mark-to-market adjustments on equity securities resulting from changes in fair value.

Other noninterest income — Other noninterest income consists primarily of loan fees and income from partnership investments accounted for under the equity method, which are out of the scope of ASC Topic 606. The items within scope of the standard primarily relate to contracts with third parties for miscellaneous referral or broker income.

Contract assets and liabilities — A contract asset balance typically occurs when an entity performs a service for a customer before the customer payment of consideration, creating a contract receivable, or before payment is due, creating a contract asset. In contrast, a contract liability balance is an entity’s obligation to transfer a service to a customer for which the entity has already received payment of consideration from the customer. The Company’s noninterest revenue streams that

are within the scope of ASC 606 are largely based on transactional activity which typically occurs at a point in time immediately after the performance obligations have been satisfied. Consideration is often received immediately or shortly after the Company satisfies its performance obligation and revenue is recognized. The Company does not typically enter into long-term revenue contracts with customers. Therefore, the Company does not experience significant contract balances. As of December 31, 2025 and 2024, the Company had no significant contract balances.