The background. Self employed client is in a repayment position every tax year by virtue of having tax deducted at source. HMRC made raised an enquiry into 2017 SA Return repaid client a smaller amount than claimed. Enquiry settled with no adjustments to original figures submitted. Client due the balance, plus repayment for 2018 year. Both amounts are marked as "pending". Called HMRC to be informed that an anonymous HMRC source/officer has flagged client as a "risk assessment" and was told that as there was no details available I would be unable to pursue it any further. Bewildering!! Has anyone come across this before and what are my options?