Self Assessment Deadlines
Self Assessment Paper tax returns
If you are completing a paper tax return and sending it via post, it must be received by HMRC by midnight on 31st October, unless you have received a letter from HMRC stating otherwise. If you receive a letter from HMRC after the 31st July requiring you to complete a self assessment tax return you will have 3 months from the date of the letter to submit you’re Self Assessment Tax Return.
Online Self Assessment Tax Returns
If you are completing your self assessment tax return online it must be received by HMRC by midnight on 31st January unless you have received a letter from HMRC stating otherwise. If you receive a letter from HMRC after the 31st October requiring you to complete a self assessment tax return you will have 3 months from the date of the letter to submit you’re return.
If you are employed under PAYE and you owe less than £3000 tax and want HMRC to collect it through your tax code you need to ensure HMRC receive your tax return by the 30th December, clearly marking on the return that you want your owed tax to be collected this way.
Payment of tax
For both paper and online self assessment tax returns the deadline for paying any tax you owe is 31st January following the end of the tax year.