Briefly:
New legislation means you need to renew your postal vote every 3 years by resubmitting a postal vote application.
Changes to postal voting arrangements are being introduced.
Existing postal voting arrangements will expire if not renewed by January 2026. The new postal voting arrangements have a limited life and will have to be renewed every three years.
Later this year: Registered postal voters will be contacted by email or by letter to both explain the changes – and to detail the actions necessary to retain the ability for individuals to cast a postal vote.
There is a .gov web site that you may find helpful here
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