What are the Self Assessment deadlines?

Different deadlines apply to the different ways in which you can submit a Self Assessment tax return.

Ways to submit your tax return…

The different ways to submit your Self Assessment tax return are:

Online – Your Self Assessment tax return can be submitted via HMRC online. Depending on your tax position you may need or prefer to process your return using commercial software.

By paper- It is still possible to complete your tax return by paper, which you should receive through the post from HMRC each year. It needs to be completed and posted back to the tax office.

Self Assessment tax return deadlines

Tax Return deadline – online

31st January: This date is the final deadline for those completing their tax returns online. There may be exceptions, for example, if you have received a notice after 31st October requesting a tax return. Typically, you will have three months to complete this. This is also the deadline to pay any due tax for both paper forms and those who file their returns online.

Tax Return deadline on paper

31st October: This is the deadline for paper tax returns whether you choose to make your own calculations or request that HMRC do it for you. However if you receive a notice to file a tax return during the tax year, you must return the form within three months of the date of issue. For example if you receive it on August 31st 2017, you have until November 30th 2017.

Tax return deadline – tax you owe

30th December: Where you are filing tax returns and also pay tax through PAYE, this is the due date where you have the option of paying your overdue tax through the PAYE method. There is an advantage here of spreading the cost of your tax over the financial year rather than as a single lump in January.

Self Assessment tax return submission – Make sure your on time

It is important to remember that late tax returns or failing to pay owed tax on time may mean that you incur extra costs through penalty fees and interest.

You should make sure you submit your Self Assessment tax return within the deadlines set by HMRC to avoid late filing penalties. If you submit your return late and don’t have a reasonable excuse you will incur late penalties which cannot be cancelled.

Reviewed by Tony Shanks, Operations Director Tax Rebate Services and member of Association of Tax Technicians (ATT)
Tax Return FAQs

Discover more about what a Self Assessment tax return is, why you have been sent one, or if you should be registering to fill one in:

SA100 is a Self Assessment tax return and is used to calculate how much tax you owe from the earnings you declare on the form…
if you are employed and have expenses because of your job which are over £2500 in any one tax year, you will normally have to complete a tax return for that tax year…
A UTR number is also known as a unique taxpayer reference number and is given to you by HMRC as part of the self assessment registration process…
Different deadlines apply to the different ways in which you can submit a Self Assessment tax return…