Self Assessment for Income Tax checklist for QuickBooks Online

Keep on top of your transactions and prepare your Self Assessment for Income Tax return with this checklist. From registration requirements to submission deadlines, we’ll guide you through each step of the way.

In this article we’ll cover:

• What is Self Assessment?
• Who needs to submit a Self Assessment tax return?
• Tax return key dates and deadlines 
• What you need to complete your tax return 
• The Self Assessment checklist

What is Self Assessment?

A Self Assessment tax return is a form you need to fill out at the end of each tax year to let HMRC know how much Income Tax and National Insurance you owe.

If you’re an employee, tax is deducted automatically from your wages or pension through Pay As You Earn (PAYE). 

However, if you’re self-employed or have other sources of income, you must submit a Self Assessment tax return, also known as the SA100 form.

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Who needs to submit a Self Assessment return?

If you are self-employed, you must submit a Self Assessment tax return for the last tax year. HMRC requires a tax return if, in the last tax year, you were:

• Self-employed and registered as a sole trader earning more than £1,000
• Earning more than £1,000 as a corporate partner

You may also need to send a Self Assessment tax return if you have any other untaxed income, such as: 

• Tips and commissions 
• Money from a renting out a property
• Income savings, investments or dividends 
• Foreign income

As a general rule, if you earn untaxed income then you need to complete a Self Assessment. Not sure if you need to submit a tax return this year? Check out the HMRC guidance and use the online checker to find out.

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Tax return key dates and deadlines

The tax year runs from 6 April to 5 April the following year. So, for example, the last tax year started on 6 April 2023 and ended on 5 April 2024. 

The deadline to submit an online return and pay is 31 January, 2025. If you can’t make your final payment by this date, you may be able to set up a Time to Pay Arrangement with HMRC. 

Here are the important deadlines for Self Assessment throughout the year:

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What you need to complete your tax return

1. Register for Self Assessment 

If it's your first time filing a Self Assessment tax return, you must register with HMRC first. This lets them know that you need to file a tax return.

2. Set up a Government Gateway account

Once you're registered, you'll get an email with your UTR, user ID, and password. Use them to create a Government Gateway account for filing your Self Assessment tax return online.

Then, sign in to your personal tax account to activate your Self Assessment.

3. Make sure that you're set up as a sole trader in QuickBooks

1. In QuickBooks, select the gear icon to open your Account and settings.
2. Select the Company tab, and then Company type. 
3. Set the tax form as Sole proprietor.
4. Select Save.

You should now be able to find the Income tax tab in the Taxes centre of your QuickBooks.

Important reminder

When making your first payment, be prepared to pay extra. This includes any tax owed from the previous year, as well as half of the estimated tax for the current tax year. In total, you'll be paying approximately 150% of the tax amount.

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The Self Assessment checklist

Now that you have everything you need to hand, let’s get started!

1. Connect your credit card and bank feeds

The easiest and fastest way to download your transactions into Quickbooks is to connect your bank or credit card account.

Here’s a list of banks that can connect to QuickBooks. Don't worry if you don't see your bank or credit card, you can add transactions manually.

Once connected, QuickBooks will automatically pull in your latest transactions every 24 hours.

2. Categorise and match all your bank transactions

The next step is to review and match all transactions so that they’re categorised correctly and up to date.

To save time, you can set up bank rules to automatically categorise common and recurring transactions. Check out this guide on the account and detail types available in QuickBooks.

If you see a duplicate transaction or a personal expense that you don't want included in your Self Assessment tax return, you can exclude or delete transactions.

3. Record all your expenses

It's always good practice to keep track of all your income and expenses throughout the year. Staying organised will make it easier for you to fill in your tax return and claim back any expenses.

Let's say you purchased something in cash or you have a transaction that doesn’t go through your bank, you can add these types of expenses manually into QuickBooks.

4. Review your Income Tax return estimate report

It’s time to review your income tax return estimate and find out how much you owe HMRC. Note, you may owe less if you’ve made payments in advance to HMRC or you if you qualify for income tax relief.

1. Go to Taxes.
2. Select VAT (Take me there).
3. Select the tax year you wish to view and select Got it.
   Tip: To see the accounts where your expenses are categorised under and the transactions recorded in those accounts, select the category.

QuickBooks calculates the estimated amount payable to HMRC based on your categorised transactions, then maps the categorised expenses directly to the boxes listed in the Self Assessment form.

You can export the information from QuickBooks and transfer it to the Self Assessment form when you’re ready to submit your return to HMRC. We’ll guide you how to do this next.

Check out the current income tax rates and bands.

5. Export and submit your Self Assessment form

After you have reviewed your Income Tax estimate, you can export the Self Assessment form from QuickBooks. However, it's important to note that you will need to submit your tax return directly to HMRC, outside of QuickBooks.

1. At the bottom of the tax summary, select Export. 
2. Copy the totals of each box from the exported file and paste them into the Self Assessment form. 
3. Sign in to the HMRC website and submit your tax return online.

After you submit you should get a confirmation message and a reference number.

6. Pay your tax bill

To avoid any fines and penalties, make sure you pay your HMRC tax bill by the deadline, which is midnight on 31 January, the same day as the filing deadline.

Check out the HMRC website for more info on paying your Self Assessment tax bill and available payment options.

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