As much as we'd like to help everybody claim hard earned cash back from the taxman we have to adhere to HMRC's criteria when deciding whether or not to make a claim. It's their rules and there is no getting round them, no matter how arbitrary they may seem.

Before we submit a tax refund claim we ask everybody a few simple questions to check whether you're likely to be successful in making a claim, here we explain why your answers to those questions might exclude you from making a claim.