Back
Let us sort your Self Assessment today. Stress-free. For £119, all in. Learn more

The most common Self Assessment mistakes

You can make filing your taxes much easier by avoiding these common Self Assessment mistakes:

1. Forgetting about deadlines

You need a UTR number for your Self Assessment.

It takes weeks to get it, so don’t wait until the last minute.

If you’re not sure about the deadlines, check our post on the UK tax year dates here.

2. Forgetting about tax reliefs

There are many ways to reduce your tax bill.

You should:

3. Forgetting about payments on account

HMRC may ask you to pay this year’s bill and also a Payment on Account.”

Your first January payment could be 50% bigger than you think.

If you’re self-employed, remember that payments on account are charged at the end of January and the end of July.

Read our guide to Payments on Account here.

4. Getting your tax code wrong

If you are under the wrong tax code, you could be paying too much tax.

Check our post on what your tax code means and how to find it.

If there’s a mistake, call HMRC as soon as possible.

5. Forgetting to declare salary and benefits from PAYE jobs

If you have a full-time job besides being self-employed, you need to let HMRC know so you don’t pay extra tax.

Ask your employer for a P60 and P11D: this will show you how much you earned and how much tax was paid.

You need to record this on the Employment pages of your tax return.

Hey there! We really hope this article helped you. Tax matters can be a dreadful topic at times. We know. That's why we started TaxScouts.
A stress-free way to getting your taxes done.

Have a minute? See how it works

More guides & useful information

Let us sort your Self Assessment online. £119, all in.

That’s right. No matter how complicated it gets or why you need to do a return in the first place, it’ll cost £119 to get it done. That includes VAT, last-minute changes and all the support you may need.

How it works

1. Answer a few simple questions

And we mean a few. After a couple of minutes of answering questions online we’ll have everything we need to start working on your tax return.

2. Then get paired with a tax accountant

That’s right, you’ll be matched with a real accountant who is best suited to prepare your return. Plus, they’re on hand for questions whenever you need.

3. We file your Self Assessment for you

Once you’ve signed off your return, your TaxScouts accountant will file your return online with HMRC. That’s it! We told you it was simple.