If you need to complete a Self Assessment tax return, you can leave the calculations to Anewthing. Provide the information and your return will be prepared, explained to you and submitted on your behalf once you have approved it. Provided the information arrives in good time, missed deadlines, penalties and late-payment interest stop being a worry.
What’s included
- Preparing and filing your Self Assessment tax return
- Checking your tax calculation and payments on account
- Personal tax planning around income, reliefs and allowances
- Making Tax Digital for Income Tax readiness and quarterly updates
- Registering for Self Assessment when you first need to file
- Dealing with HMRC letters and enquiries
How we work with you
Talk it through
Tell us what you need and how your records are kept.
Agree the scope and fee
You know what is included and what it costs before work begins.
Ongoing support
Deadlines and rule changes are raised with you before they become urgent.
Current rules at a glance
| Register for Self Assessment | By 5 October after the end of the tax year in which you need to file |
|---|---|
| Paper tax return | By 31 October after the end of the tax year |
| Online tax return and balancing payment | By 31 January after the end of the tax year |
| Second payment on account | By 31 July |
| Late filing penalty | Standard Self Assessment: initial £100 penalty, with further charges after 3, 6 and 12 months. MTD uses different rules. |
| Making Tax Digital for Income Tax | Quarterly updates due 7 August, 7 November, 7 February and 7 May; no penalty points for late quarterly updates in 2026–27 |
Common questions
When is my tax return due?
For online returns, the deadline is 31 January following the end of the tax year on 5 April. Paper returns are due by 31 October. Any tax owed is normally payable by 31 January, with payments on account due on 31 January and 31 July for many taxpayers.
Does Making Tax Digital for Income Tax apply to me?
It depends on your qualifying income from self-employment and property. See the article on Making Tax Digital for Income Tax for the current thresholds and dates, or ask Anewthing to check your position.