Auditing firms enlisting the accounting services of other businesses to comply with the amended auditor independence standards should proceed with caution, the ATO says.

Audit pooling arrangements to sidestep restructuring costs and comply with new audit independence standards carries many risks, the ATO has noted in new guidance.

The ATO has specified two situations under which it will not allow tax agents to perform an SMSF audit, adding to its practical guidance around the issue.