Hi Jacqui,
The working requirements for Universal Credit is covered by the Claimant Commitment. There is guidance here-:
Universal Credit and your claimant commitment
It is for you to decide on what is better for your individual financial circumstances as to whether to end the Tax Credits claim or not. You should speak with both Universal Credit and Tax Credits to consider the impacts before making a decision.
If you want to end your Tax Credits claim, there is guidance on how to do this here-:,
End your tax credits.
Thank you.