When is the self-assessment tax return deadline – and what happens if I miss it?
The deadline for filing your online Self assessment Tax return for the tax year ending on 5 April 2017 is 31st January 2018.
If you miss this deadline by just one day you're already looking at a £100 fine.
- After 3 months, an additional £10 per day up to £900!
- After 6 months, a penalty of 5% or £300, whichever is greater
- After 12 months, another 5% or £300, whichever is greater
- This could lead to a £1600 fine, without even paying any tax owed!