Making Tax Digital
Making Tax Digital for Income Tax 2026/27 — Who Must File Digitally
6 April 2026
From 6 April 2026, sole traders and landlords over £50,000 gross income must keep digital records and send quarterly updates to HMRC.
Guides
Self Assessment insights
Practical notes on Self Assessment forms, deadlines, Making Tax Digital and how the software maps to HMRC pages.
Self Assessment
Self-Assessment Tax Return Deadlines 2025/26 — Key Dates You Must Know
6 April 2026
The dates that matter for the 2025/26 tax year, from 6 April through payments on account.
Error 1046 Guide
Error 1046 — What It Means and How to Fix It
12 March 2026
HMRC validation error 1046 usually means a figure or box combination is inconsistent.
Government Gateway
How to Add Taxes to Your Government Gateway Account
2 February 2026
Self Assessment must be activated on your Gateway account before commercial software can submit.
Government Gateway
What Is a Government Gateway User ID and How Do You Get One?
20 January 2026
Commercial software still needs a Gateway user ID even if you normally use One Login.
Employment
What is a P60 and Why Is It Important for Your Tax Filing?
10 January 2026
Your P60 summarises pay, tax and National Insurance for the year — it drives SA102.
Employment
What is a P11D? A Guide for Employees
8 January 2026
P11D reports benefits in kind such as company cars and private medical insurance.
Self Assessment
Residence, Remittance (SA109)
20 October 2025
SA109 covers residence, domicile, split year treatment and the remittance basis.
Self Assessment
Can I amend my Self Assessment tax return after filing?
18 October 2025
Yes — usually within 12 months of the 31 January deadline, after waiting 72 hours.
Self Assessment
Trust Income (SA107)
15 October 2025
Report income from trusts, settlements and deceased persons' estates.
Self Assessment
Foreign Income (SA106)
14 October 2025
Overseas employment, property, savings, dividends and foreign tax paid.
Self Assessment
Property Income (SA105)
13 October 2025
UK land and property, including Furnished Holiday Lettings in the UK and EEA.
Self Assessment
Partnership Income (SA104)
13 October 2025
Your share of trading or property partnership profits.
Self Assessment
Self Employment (SA103)
13 October 2025
Business income, expenses, capital allowances and CIS deductions.
Self Assessment
Employment Income (SA-102)
12 October 2025
Salary, bonuses, benefits and expenses from employment.
Self Assessment
Self Assessment (SA100)
12 October 2025
The main return — personal details plus interest, dividends and pensions.
Support
Questions about your return?
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