31 July · Official deadline
Second payment on account
The second instalment towards your Self Assessment bill.
GOV.UKFiling, penalties and appeals
The dates that protect your money and your right to fight
Pick your country. See what to file, when penalties begin, and how long you have to challenge a decision. Every step opens the official source.
Tax year
6 April to 5 April the following year
HMRC deadlines do not move for weekends. If the last day is a Sunday, the money still has to clear by then.
File and pay
5 October · Official deadline
Register for Self Assessment
Tell HMRC you need to file for the tax year that ended in April.
GOV.UK31 October · SA100
Paper return deadline
Last day for a paper Self Assessment return.
GOV.UK30 December · Official deadline
Ask to pay through your tax code
File online by now if you want up to 3,000 of tax collected through your PAYE code instead of in one lump.
GOV.UK31 January · SA100
Online return and balancing payment
File online and pay the balance for the tax year that ended in April, plus your first payment on account.
GOV.UK1 March · Official deadline
Late payment penalty bites
A 5 percent surcharge on tax still unpaid from 31 January.
GOV.UKPenalties, payment help and appeals
The date on your own notice wins. Appeal periods often start when the authority sends that notice, not at the tax year end.
appeal
Appeal a late filing or payment penalty
Usually within 30 days of the penalty notice
Use the date printed on your notice. A late appeal needs an explanation.
Download SA370file
Online Self Assessment return and payment
31 January after the tax year
The paper return deadline is normally 31 October.
Open SA100penalty
First late payment penalty
30 days after the 31 January payment deadline
Interest starts earlier. Ask for Time to Pay as soon as you know you cannot pay.
Open Payment or Time to PayOfficial library connection
The library holds the official rules behind these dates. Source checks can flag a change, but a person must approve it before Taxmiser changes a calculation.