An accounting firm opened an account at a bank that is intended to be used...

this activity is unusual and inconsistent with the expected behavior of an accounting firm’s operational account. The account should normally receive fees from clients that are proportional to the services rendered and reflect the market rates. Receiving international payments that are substantially higher than other fees could indicate that the account is being used to launder money or finance terrorism by disguising illicit funds as legitimate income. This could trigger a red flag for the bank and prompt a comprehensive review of the account.

ACAMS Study Guide 6th Edition, Chapter 1, Section 1.6, page 24: “Methods to launder money used in banks and other deposit taking institutions”.

ExamTopics, Question 446: “An accounting firm opened an account at a bank that is intended to be used as the operational account for the business. After a few months, a comprehensive review of the account was triggered due to unusual activity on the account. Which most likely triggered the review?”