Tax Return: The last step in running your own business

Updated on August 6, 2025

Welcome to the 2024/25 edition of our tax return guide. New screenshots, updated rules, same chill walkthrough. Jo did hers already (you're welcome), and now it's your turn. Let’s do this together – biscuits optional but encouraged.

What you need before you start

• Your Government Gateway ID & password
• Your P60s or P45s for any employed work
• Income and allowable expenses for self-employed work
• Any foreign income, bank interest, dividends, or gains
• Access to the SansDrama Web App for quick copy-and-paste

Pro tip: Use this article in one tab and your HMRC return in another. That way you can follow step-by-step.

Step 1: Sign in and Security Setup

Head to www.tax.service.gov.uk/gg/sign-in and log in. If prompted, get your 2FA code via text/email/app. Tick 'remember for 7 days' to keep things smooth.

HMRC may ask for a recovery word or confirm your email for digital letters. Set up your preference and continue through the prompts.

Step 2: Getting started

Once you're on your 'tax homepage', click into the Self Assessment section.

Then click on "Complete tax return":

Then click "Start Now":

At this point, if you had employed work this year, you may be shown some details HMRC has already received to confirm:

Step 3: Tell us about you

This section is where you confirm some personal details to HMRC, such as your address - you shouldn't need too much guidance at this stage!

Step 4: Tailor your return

Okay, so you have 3 pages of questions here for HMRC to work out what information is relevant for your tax return. This form is used for everyone so it has to cover a lot of different scenarios - don't panic because most of it sounds like gobbledygook and ask start thinking 'maybe I do have a spouse born before 6 April 1935...'.

Key for 1 of 3 is employed work, self-employed work, and foreign income. When you select the number of employed or self-empoyed jobs you had, it will give you a text box for each for you to give the name.

There's probably not much in page 2 that's relevant for the average performer - maybe interest income:

And on page 3, you may have made a relevant pension contribution but check the article for the explicit occasions that you need to include this as it is not always:

Step 5: Employed Income (if any)

Check your P45/P60. Fill in the boxes or verify pre-filled info. Confirm if you were a director or received any benefits – most people say 'No'. It asks about company cars and private medical because they're taxable benefits.

You can probably leave this one empty:

Step 6: Self-Employed Income

You will have the same ten(!) pages to enter for each self-employed business (it says 'X of 2' for details but there are more to follow) you added within the 'Tailor your return' section. If your income is under £90k, tick 'No' to VAT and, in all likelihood, you want to click 'No' to the basis period question. Once you've done this, a raft of other questions arrive - check through them all but, most of the time, the answer is 'None of these apply', which is the box right at the bottom.

On page 2, enter your business name and profession (e.g. 'Performer'). Enter total income and expenses. Leave boxes blank if not applicable (don’t type 0).

Quick accounting admin page - if you don't know any different, your books are made up to 05/04/2025 (the last day of the tax year). The traditional accounting question is optional, so feel free to leave unchecked unless you know one way or the other.

Time for some numbers! Enter total income and expenses. Leave boxes blank if not applicable (don’t type 0). Suggest you input your expenses as a 'single total value' for ease.

We're assuming you want to leave the whole 'Capital allowance...' page blank unless you have something cool going on...

The next 3 pages are all about tax adjustments - for most people the answer is to leave it blank.

Then you have a question about whether you are exempt from Class 4 NICS. Most will want to select 'None of these apply' - perhaps you were either too young or you were not tax resident for the year...? Class 4 National Insurance is a 6% tax on profits above £12,570 (reducing to 2% over £50,270) - we cover all this in our National Insurance post.

Then there's a page asking for any other info...

...followed by a summary of self-employed performance leading to a taxable profits number.

Next up is Class 2 National Insurance - fully voluntary this year for the first time. There are some scenarios where you may wish to pay voluntarily if it helps you with your contribution record towards state benefits (pension, maternity pay etc) but for most, you can say 'No'.

Now two pages asking about Underpaid tax - this allows you to pay back via your tax code with an employer rather than a lump payment. We've only ever had £0.00 here, so hasn't been relevant - the idea is it alleviates the cash flow burden of paying this upfront when the number is not too big.

Page about overpaid tax that you have to click through - the instructions are clear:

Next page is a bit like the Underpaid tax ones but for this year - it's basically allowing you to roll some of your tax burden into your tax code next year to be paid in your PAYE salary.

We're nearly at the end of The Great Clickthrough that happens at the end of every tax return - 3 more to go. Any adjustments? Probably not:

Any provisional numbers (i.e. you've estimated because the exact number is not yet knownn)? Rare if you use cash basis (or at all in this business):

Then a text box and file upload if there is anything you need to show HMRC to support your return for some reason - again, usually a clickthrough...

If you didn't have any other interesting sections to add, such as Foreign Income, then you are done here and will see a summary of sections all complete.

Step 7: Finalise and Submit

You then get your first site of what you owe, unless you use the SansDrama App and have known all along! Hopefully, no unpleasant surprises here. Note it shows you your tax bill for this year as well as your payments on account for next year.

Clicking through this takes you to a breakdown of your tax calculation:

Followed by the opportunity to download your return in various formats.

And finally, you can submit! Easy! It will make you go through the login again to make sure it's still you.

Step 8: Foreign Income

Screenshots to be updated shortly! Only complete this if you paid tax abroad. Include country, amount paid, and amount received (converted to GBP). Use our conversion guide if needed.

Deadline

• Online returns: 31 Jan 2026
• Tax due: 31 Jan 2026

🎉 You’re all done. Give yourself a high five. Or a biscuit. Or both.

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