An accountant’s certificate of type ISAE 3402 documents proper IT conditions at a company and acts as proof that you meet legal requirements and good IT usage.
Some companies get an ISAE 3402 made due to demands from customers and business partners; others get them to send a signal of credibility and security to existing and potential customers. Simply a legal requirement that in certain industries or services you must have an auditor’s statement or that you need a supplier who has an auditor’s statement.