I don't think it's on the SA form. I seem to remember a button on your 'profile' page somewhere. I did it last year.
Thanks! Just found it.
From your profile - self assesment - view your tax year overview - reduce payments on account.
EDIT - There is also an option to reduce your payments on account after the 'your tax calculation' section when completing self-assesment.
@farewell started
London Fixed Gear and Single-Speed is a community of predominantly fixed gear and single-speed cyclists in and around London, UK.
This site is supported almost exclusively by donations. Please consider donating a small amount regularly.
I don't think it's on the SA form. I seem to remember a button on your 'profile' page somewhere. I did it last year.