You may receive correspondence from HMRC whether it is unexpected or about an issue that you may be already aware of, an account will be able to liase with them on your behalf if you wish to take the stress off you.
An account will be able to help clients who are behind on self-assessment, to advising on informing HMRC on undeclared income. From investigations to routine VAT inspections an accountant will be able to help you deal with all these enquires.