Attest Service

What Is an Attestation Service?

An attest service, or attestation service, is an independent review of a company's financial statement conducted by a certified public accountant (CPA). The CPA delivers an attestation report with conclusions about the reliability of the data.

The standards for attestation services are developed and published by a professional services group, the American Institute of Certified Public Accountants (AICPA). In recent years, the standards have been updated to reflect a wider range of attest services unrelated to financial reports. For instance, a company might request an attest service on its consumer privacy statement.

Understanding the Attest Service

In law, an attestation is a declaration by a witness that a legal document was properly signed in the presence of the witness. Essentially, it confirms that a document is valid. A notary public provides an attestation for documents.

In finance, an attestation service is a CPA's declaration that the numbers are accurate and reliable. As the service is completed by an independent party, it validates the financial information prepared by internal accountants.

There are three main types of attest functions including a comprehensive examination, a review of an examination completed by another party, and a partial examination that is limited to an analysis of specific procedures.

All three attest functions must follow standards set by the AICPA with respect to audit procedure, independence, and expression of opinion.

CPAs increasingly are asked to perform attest services on non-financial documents such as security and privacy control statements.

The attestation review is one of the most important duties of a CPA. In 2011, Statement on Standards for Attestation Engagements (SSAE) No. 16 replaced Statements on Auditing Standards (SAS) No. 70 as the authoritative guide for CPAs performing audits.

This document, called AT Section 801 of SSAE No. 16, outlines the goals of an attest function. It also broadens the definition. According to AICPA, certified public accountants increasingly are being asked to perform attest services on non-financial procedures. These often are meant to prove compliance with complex government regulations and requirements. They might include reports on security procedures, privacy controls, and greenhouse gas emission reports, to cite a few examples.