Hi,
If your income has changed, then yes, you can submit a SA303 to reduce the payments on account. You would need to estimate your income and check if all your tax would be deducted at source before reducingthe amounts to nil. If you reduce the amounts to nil and there is a balance due once the tax return is processed then the payments on account will be reintroduced to cover the balance and interest can be charged. You can see information on payments on accout here:
Payments on account
Thank you.