Late self assessment fines and penalties

If you’ve missed the 31 January deadline for self assessment, at the very least, you are going to have a fine of £100.

The tax year ends on the 5th April and by the following 31 January you must:

  1. File your Self Assessment tax return
  2. Pay the tax owing on your Self Assessment tax return

Failure to do either of these can lead to fines and penalties. There are a series of penalties for not filing you return and a separate series of penalties for not paying the tax you owe. It all adds up quickly!

Fines & penalties for late return of Self Assessment

  • 1st Feb (return 1 day late) £100 fine from the 1st February.
  • 1st May (return 3 months late) £10 a day fine up to a maximum of £900 (90 days) for every day it is late
  • 1st Aug (return 6 months late) £300 fine or 5% of the tax owing, whichever is greater
  • 1st Feb (return 12 months late) £300 fine or 5% of the tax owing, whichever is greater

Fines & penalties for late payment of tax owing

  • 1st March (payment 30 days late) 5% charge on the tax owing on that day
  • 1st August (payment 6 months late) 5% charge on the tax owing on that day
  • 1st Feb (payment 12 months late) 5% charge on the tax owing on that day

Interest is charged on the tax owing including the amount levied in charges at a rate of 3%.

For more information HMRC provides a useful self assessment penalties  breakdown.