Bydd yr ail Orchymyn cychwyn yn dwyn i rym, ar 1 Ebrill 2021, y rhan fwyaf o Bennod 1 o Ran 6 o'r Ddeddf mewn perthynas â pherfformiad a llywodraethu prif gynghorau.  Bydd Pennod 3 o'r Rhan honno, sy'n darparu ar gyfer cydgysylltu rhwng rheoleiddwyr, hefyd yn dod i rym ar 1 Ebrill 2021.
The second commencement Order will bring into force, on 1 April 2021, the majority of Chapter 1 of Part 6 of the Act in respect of the performance and governance of principal councils.  Chapter 3 of that Part, which provides for co-ordination between regulators will also come into force on 1 April 2021.