A further return therefore needs to be submitted by 30 January 2027 with the additional tax calculated as though the lease were a 7 year lease.
Gan hynny, mae angen cyflwyno ffurflen dreth ychwanegol erbyn 30 Ionawr 2027 gyda'r dreth ychwanegol yn cael ei chyfrifo fel pe bai'r les yn les 7 mlynedd.