Self Assessment Tax Return in London

Who needs to complete a self assessment tax return


What are the main things I need to know about self assesment


Tax year

A tax year runs from 6 April to 5 April. A tax return must be filed electronically by 31 January the following year or by 31 October if you are filing using a paper tax return.

Payment dates

Tax must be paid by 31 January following the 5 April tax year. If you fall under the "payment on account" rules, you must also make a payment in respect of the following year on 31 January and 31 July.

What if I do nothing


Tax penalties

If you have a reasonable excuse, HMRC will remove the penalties. What you think is reasonable might be at odds with HMRC and often these disputes are taken to a tax tribunal for an independant decision. If HMRC disagree with your excuse, the following HMRC tax penalties await you:

  • 1 day late - £100
  • 3 months late - £10 per day, a max of £900
  • 6 months late - £300
  • 12 months late - £300


If you will struggle to pay you tax bill - HMRC may agree a time to pay arrangement with you depending on your personal circumstances. If you don't speak to HMRC and don't pay your tax the following interest charges appy:

  • 5% - if the payment is 30 days late
  • A further 5% - if the payment is 6 months late
  • A further 5% - if the payment is 12 months late

How we can help


Offer a free consultation

Do you have an issue/problem and want a non-obligation chat? We are happy to help.

Provide tax advice

We can provide you with a plan for the future or help you get out of a problem now.

Calculate your tax

The UK tax system is amongst the most complex in the world. We are trained and highly experienced and great at explaining.

Deal with HMRC

HMRC are helpful most times but if the thought of dealing with them is daunting, leave it us. We have years of experience and can help.