* Are they members of a recognised professional body from which you can seek redress if things go wrong?
* Do they offer tax planning advice or merely an execution only tax shop to help with form filling?
* How much will they charge, including VAT?
* Does the quoted fee include insurance against unforseen cost over-runs, such as the Inland Revenue deciding to investigate your return?
* Will your account be handled by an experienced partner in the firm or a less qualified junior?