The WRA can also make an assessment (also known as a ‘WRA assessment’) against any amount of tax and associated interest which has (but should not have) been repaid to the taxpayer.
Gall ACC hefyd wneud asesiad (a elwir hefyd yn ‘asesiad ACC’) yn erbyn unrhyw swm o dreth a llog cysylltiedig sydd wedi cael ei ad-dalu i'r trethdalwr (ond na ddylid bod wedi ei ad-dalu).