Rarely can congregations pay for a full-blown audit of the church books by a CPA. Audits are expensive, often ranging from $5,000 to $15,000 depending on the annual budget of the organization.
An alternative is a management review of the congregation’s cash management procedures, which can be done by any other accountant or experienced church bookkeeper. This should be done at least once every three years, usually before a new treasurer or bookkeeper takes office. Sample Internal Financial Review (PDF)
A cash management review should include:
Verifying that the accounts payable policies and procedures are being followed,
Reviewing the system for recording and reporting pledges and contributions
Comparing bank statements to income/expense reports to spot check for irregularities