Erbyn hyn, mae Llywodraeth y DU yn bwriadu cyflwyno deddfwriaeth sylfaenol a gaiff yr effaith o ddileu'r trethi busnes ôl-ddyddiedig ar gyfer pob eiddo a holltwyd mewn perthynas â rhestr drethi 2005 (eiddo busnes a rannwyd yn fwy nag un eiddo ac a brisiwyd ar wahân) sydd â biliau trethi wedi'u hôl-ddyddio o leiaf 33 mis, lle gwnaed y newid i'r rhestr cyn 1 Ebrill 2010.  Ni fydd biliau trethi ôl-ddyddiedig trethdalwyr sydd ag atebolrwydd ôl-ddyddiedig tebyg, ond y mae natur eu heiddo, fel y nodir ar y rhestr brisio, wedi newid ar ôl 1 Ebrill 2010, yn cael eu canslo.   Hefyd, byddai trethdalwyr y caiff eu prisiad ei ddiwygio heddiw, a'i ôl-ddyddio i 2005, yn dal i orfod talu eu trethi ôl-ddyddiedig, fel unrhyw drethdalwr y mae ei eiddo wedi'i hollti ac sy'n creu atebolrwydd ôl-ddyddiedig ar ôl 2008.
The UK government has now introduced primary legislation via the Localism Bill, which will give it power to make regulations cancelling the backdated business rates liability for all split properties in England (business premises split in to more than one property and valued separately) appearing on the 2005 rating list, which have backdated rates bills of at least 33 months, and where the change to the list was made before 1 April 2010. Ratepayers with similar backdated liabilities, but whose entry on the valuation list is changed after 1 April 2010 will not have their backdated rates bills cancelled. Also, ratepayers who today have their valuation amended and backdated to 2005, would still have to pay their backdated rates, as would any ratepayer whose  property is split and incurs a backdated liability after 2008.