If you have a Countryside Stewardship Mid / Higher Tier or Water Capital Grant agreement with a January 2021 start date, the deadline for completing and paying for capital works is 31st December 2022.
It is vital that you have evidence to show payment for materials, contractors etc. has cleared your bank account before the 31st December, as RPA can ask to see bank statements as part of claim evidence. Therefore, you'll need to ensure you get all invoices associated with capital works paid before the Christmas break.
You then have until 31st March 2023 to submit your claim and supporting evidence to the RPA.