Anyone making a claim for an amount of tax to be repaid or discharged, must keep and preserve records in relation to that claim until the latest of the following:
Rhaid i unrhyw un sy’n gwneud hawliad am swm o dreth i’w ad-dalu neu ei ryddhau gadw cofnodion mewn perthynas â’r hawliad hwnnw a’u storio’n ddiogel nes yr olaf o’r canlynol: