You are correct if you did not pay then the amount would be larger. If you don’t pay your tax on time, you’ll probably have to pay interest on the outstanding amount. You may also have to pay a penalty.
HM Revenue and Customs (HMRC) will ask you about:
If HMRC believes you can pay all they will expect you to pay immediately and take payment over the phone by direct debit, credit or debit card.
Your ability to pay them less will be decided by HMRC.
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