Gwnaed cynnydd pellach pan gytunodd Llywodraeth y DU ar welliant i ehangu'r diffiniad o drais difrifol i gynnwys cam-drin domestig fel y'i diffinnir yn Neddf Cam-drin Domestig 2021 a throseddau rhywiol fel y'u diffinnir yn Neddf Troseddau Rhywiol 2003. Mae'r ehangiad hwn yn golygu y bydd yn ofynnol i awdurdodau lleol, yr heddlu, awdurdodau tân ac achub, asiantaethau cyfiawnder troseddol penodedig ac awdurdodau iechyd gynnwys cam-drin domestig a thrais rhywiol yn eu strategaethau trais difrifol o dan y Ddyletswydd Trais Difrifol.
Further progress was made when an amendment to expand the definition of serious violence to include domestic abuse as defined in the Domestic Abuse Act 2021 and sexual offences as defined in the Sexual Offences Act 2003 was agreed by the UK Government. This expansion means that local authorities, the police, fire and rescue authorities, specified criminal justice agencies and health authorities will be required to include domestic abuse and sexual violence in their serious violence strategies under the Serious Violence Duty.