Key dates for the UK tax year 2019/20

1 January 2020
Payment of Corporation Tax by companies with 31 March 2019 year-end.
If you have a limited company with a year-end of 31 March then your Corporation Tax will be due to be paid by 1 January 2020. This date adjusts depending on your year-end, for example, Corporation Tax will be due by 1 September for companies with a 30 November year-end (9 months and 1 day after year-end). The late payment rate is currently 2.75%.
14 January 2020
Form CT61 filed and tax paid for the quarter ended 31 December 2019.
Form CT61 is used to claim the return of Income Tax or pay relevant tax if your company or organisation pays interest, royalties, manufactured payments or similar recurring payments.
31 January 2020
Online submission deadline for 2018/19 Self Assessment income tax returns.
31st January is the biggest date in the tax calendar for many self-employed people and small business owners.

If you’ve earned any income outside of PAYE tax, you’ll need to submit a Self Assessment tax return, which is the document that tells HMRC what you’ve earned and what you need to pay in tax.

Self Assessment income tax returns are due by midnight on 31st January for the previous tax year 2018/19 but get it done with plenty of time to spare so it isn’t stressful.

If you miss the deadline HMRC will charge you a penalty of £100 if it’s up to three months late (more if it’s later).

31 January 2020
Balancing payments of Income Tax for 2018/19 and the first payment on account for 2019/20. Payment of Capital Gains Tax for 2018/19.
On 31 January you also need to submit your first payment on account for the 2019/20 tax year if you’re self-employed. The second payment on account follows six months later. If you owe any money for the previous tax year, the balancing payment will also be due on this date.
5 March 2020
ONE MONTH TO GO!
Get all your pre-end of tax year planning done.
The end of the personal tax year is one month away today so it’s worth putting this date in your diary to make sure you have everything you need in place. It’s also the time to make any tax-efficient investments for the current tax year.
31 March 2020
Corporation Tax returns filed by companies with 31 March 2019 year-end.
If you have a limited company with a year-end of 31 March then your Corporation Tax will be due to be filed by 31 March 2019 for 2018. The late payment rate is currently £100 (increasing the longer it is late).
5 April 2020
2019/20 tax year ends.
The end of the personal tax year. Get ready to do it all again!