Guidance and regulation

Use the Check Employment Status for Tax (CEST) tool to find out if you, or a worker on a specific engagement, should be classed as employed or self-employed for tax purposes.

• From: HM Revenue & Customs
• Updated: 4 May 2021

Find and use tools and calculators that will help you work out your tax.

• From: HM Revenue & Customs
• Updated: 28 March 2024

Off-payroll working rules for clients, workers (contractors) and their intermediaries.

• From: HM Revenue & Customs
• Updated: 15 December 2023

How to get online help with Self Assessment from HMRC by using our digital assistant, community forums, YouTube videos and online tools.

• From: HM Revenue & Customs
• Updated: 22 September 2023

Find software suppliers for tax returns, supplementary pages and attachments.

• From: HM Revenue & Customs
• Updated: 25 April 2024

Rates, allowances and limits for National Insurance.

• From: HM Revenue & Customs
• Updated: 6 April 2024

Find out which mortgage providers and lenders accept printed tax summaries.

• From: HM Revenue & Customs
• Updated: 8 June 2020

When to apply the off-payroll working rules (IR35) if you receive services from a worker through their intermediary.

• From: HM Revenue & Customs
• Updated: 8 March 2023

Supplementary guidance on how to check tax calculations or work out the trading profits of a business for Self Assessment tax return.

• From: HM Revenue & Customs
• Updated: 13 March 2024

Learn more about your responsibilities if you're running a small business including registration, tax returns, record keeping, tax bills and payments.

• From: HM Revenue & Customs
• Updated: 16 April 2024

How to comply with the reformed off-payroll working rules (IR35), and avoid common mistakes.

• From: HM Revenue & Customs
• Updated: 15 December 2023

Check how much you were paid for SEISS and how to repay an overpaid grant.

• From: HM Revenue & Customs
• Updated: 9 March 2022

How Income Tax and National Insurance contributions rules work if you’re a share fisher.

• From: HM Revenue & Customs
• Updated: 6 April 2024

If you operate as a business, find out if you need to include a COVID-19 grant or support payment on your tax return.

• From: HM Revenue & Customs
• Updated: 16 September 2023

Find out what to do if you need to pay back some or all of a SEISS grant.

• From: HM Revenue & Customs
• Updated: 10 January 2022

The taxation of payments received from domestic and non-domestic Renewable Heat Incentive schemes.

• From: HM Revenue & Customs
• Updated: 14 October 2015

This factsheet explains the checks on tax affairs when HMRC visits a business premises unannounced.

• From: HM Revenue & Customs
• Updated: 15 May 2023

Advice about what records to keep for tax purposes and how long to keep them.

• From: HM Revenue & Customs
• Updated: 1 February 2013

Use this technical documentation for partnership returns if you’re a software developer working with the Self Assessment online service.

• From: HM Revenue & Customs
• Updated: 22 April 2024

Information on how to account for redress payments on your tax return.

• From: HM Revenue & Customs
• Updated: 24 January 2017