How to fill in a Self Assessment tax return

Do I need to fill in a Self Assessment tax return?

Yes, if:

  • your self-employment income was more than £1,000 (before taking off anything you can claim tax relief on)
  • your income from renting out property was more than £2,500 (you’ll need to contact HMRC if it was between £1,000 and £2,500)
  • you earned more than £2,500 in untaxed income, for example from tips or commission
  • your income from savings or investments was £10,000 or more before tax
  • you need to pay Capital Gains Tax on profits from selling things like shares or a second home
  • you’re a director of a company (unless it was a non-profit organisation, such as a charity)
  • you, or your partner’s, income was over £50,000 and you’re claiming Child Benefit
  • you have income from abroad you need to pay tax on, or you live abroad but have an income in the UK
  • your taxable income was over £100,000
  • if you earn over £50,000 in the 2020/21 tax year and make pension contributions you might have to complete an assessment to claim back the extra tax relief you’re owed
  • you’re a trustee of a trust or registered pension scheme
  • your State Pension was more than your personal allowance, and your only source of income
  • you received a P800 from HMRC saying you didn’t pay enough tax last year.

You can also fill in a Self Assessment tax return if you want to make voluntary Class 2 National Insurance contributions. This will help you qualify for benefits such as the State Pension.

You usually don’t need to fill in a Self Assessment tax return if you’re an employee who has paid tax through the Pay As You Earn (PAYE) system. This is unless you earned over £100,000.

How to register for a Self Assessment tax return?

Registering for Self Assessment

If you’ve never submitted a return before, you’ll first need to register for Self Assessment.

There are different ways to register if you’re self-employed, not self-employed but need to declare income, or if you’re in a partnership.

When you’ve registered, you’ll be sent your Unique Taxpayer Reference (UTR).

If you want to submit your Self Assessment form online, you’ll then need to set up a Government Gateway account. To do this, follow the instructions in the letter containing your UTR.

When you’ve set-up the account, you’ll get an activation code in the post. You’ll then need to complete the set-up of your Gateway account.

If you’ve submitted Self Assessment tax returns before, you’ll need your old UTR to register and set up the account.

It’s best to make sure you can access you Gateway account before you try to submit your Self Assessment. This saves time if, for any reason, you can’t log in.

What are the Self Assessment deadlines?

You submit tax returns for tax years, not calendar years. And you do this in arrears.

For example, for the 2020/21 tax year – running 6 April 2020 to 5 April 2021 – you would:

  • need to register for Self Assessment by 5 October 2021 if you’ve never submitted a return before
  • submit your return by midnight 31 October 2021 if filing a paper tax return
  • submit your return by midnight 31 January 2022 if filing online
  • pay the tax you owe by midnight 31 January 2022.

If you fail to meet one or more of these deadlines, you might be charged a penalty fee and interest on late payments.

What information will I need to fill in a Self Assessment tax return?

If you’ve never filled in a self-assessment tax return before, it can look daunting. But when you understand the process, it’s relatively simple – as long as you have all the information you need.

Before you start, make sure you have:

  • your ten-digit Unique Taxpayer Reference (UTR)
  • your National Insurance number
  • details of your untaxed income from the tax year, including income from self-employment, dividends and interest on shares
  • records of any expenses relating to self-employment
  • any contributions to charity or pensions that might be eligible for tax relief
  • P60 or other records showing how much income you received that you’ve already paid tax on.

It’s also a good idea to read the relevant HMRC help sheets. Particularly on the extra sections, or supplementary pages, that relate to why you’re filling in the Self Assessment tax return.

If you’re filling in your Self Assessment form online, you can also find helpful online by clicking the ‘?’ next to the different fields.

How to fill in a Self Assessment tax return

There are two sections to a Self Assessment tax return. The main section is the SA100, which deals with:

  • taxed and untaxed income in the form of dividends and interest
  • pension contributions
  • charitable donations
  • benefits, including State Pension, Child Benefit and Blind Person’s Allowance.

Do you have income to declare as a company director, a foreign national (or dual resident), from self-employment, property, Capital Gains, or from abroad? Then you’ll also need to fill in a supplementary page.

You don’t have to fill in the short-form tax return (SA200), HMRC send it to you.

How to fill in the main tax return (SA100)

Before you start filling in the SA100 or the supplementary pages, it’s important to read the help sheets and notes related to the section.

Income

This section is specifically for:

  • declaring tax and untaxed income from interest earned from bank and building society accounts, and
  • dividends from shares.

Pensions, annuities and benefits

If you’re retired, you need to enter the:

  • total amount of State Pension you were entitled to receive over the tax year
  • gross amount of any State Pension lump sum
  • gross amount of any annuities or pension lump sums (other than State Pension).

If you’re claiming benefits, you’ll need to enter the:

  • amount received in Incapacity benefit and Jobseeker’s Allowance
  • grand total of taxable benefits received – this includes Bereavement Allowance, Carer’s Allowance and Industrial Death Benefit.

You don’t need to include:

  • Attendance Allowance
  • lump sum Bereavement Support Payment
  • Personal Independence Payment (PIP)
  • Pension Credit
  • Working Tax Credit
  • Child Tax Credit
  • income-related Employment Support Allowance
  • Maternity Allowance, or
  • War Widow’s Pension.

These benefits aren’t taxable.

Other UK income

This section is for any other taxable income, not related to interest, dividends or on the supplementary pages.

You can also enter any allowable expenses related to this income, and any income tax you’ve already paid on it.

Pension contributions

Any payments into a registered pension scheme, annuity contract, or employer’s scheme where deductions were made after tax.

Charitable donations

Grand totals of Gift Aid donations made to charities during the tax year. You can also enter amounts for any shares, securities, land or buildings gifted to charities.

Blind Person’s Allowance

Confirm whether you’re claiming Blind Person’s Allowance.

Student loan repayments

Confirm whether you’re currently repaying your Student Loan and deductions made by your employer.

High income Child Benefit charge

You only need to fill in this section if you’re receiving Child Benefit and your income was over £50,000.

Marriage Allowance

Complete this section if your income for the tax year was less than the Personal Allowance, and you want to transfer some of your Personal Allowance to your spouse.

How to complete the supplementary pages of a Self Assessment tax return?

Do you have extra income to declare from self-employment, property or capital gains? Then you’ll need to fill in a supplementary page. If you’re:

  • self-employed, you need to complete SA103
  • reporting property income, fill in SA105
  • declaring capital gains, complete SA108.

In these pages, you’ll need to report income from these sources that you haven’t paid tax on.

You’ll also get to declare any allowable expenses, which will be deducted from your tax bill.

Self-employed (SA103)

Income

If you’re earning money through self-employment, you’ll be asked to enter your turnover under the business income section.

This is the grand total of everything you had coming in during the tax year, before expenses are deducted.

If you have more than one source of self-employed income, you can enter this amount separately. But make sure the job you earn the most from is your main employment.

Expenses

What expenses can I include in my Self Assessment tax return?

There are two ways to declare your expenses if you’re self-employed.

If your annual turnover is below £85,000, you can just enter your total expenses without having to itemise them.

If you’re self-employed and your turnover is more than £85,000, you’ll have to enter an individual amount for each kind of expenses, plus a total at the end.

The different expenses you can include if you’re self-employed are:

  • cost of stock bought for resale
  • cost of equipment used at work
  • wages, salaries and other staff costs
  • payments to subcontractors (if you work in the construction industry)
  • vehicle and travel expenses
  • work building costs (including rent, power and insurance)
  • repairs and maintenance for work buildings and vehicles
  • office costs (including internet access, phones and stationery)
  • advertising and business entertainment costs
  • interest on loans
  • bank, credit card and other financial charges
  • accountancy, legal and other professional costs.

You don’t need to send in proof of your expenses, such as receipts, when you submit your Self Assessment tax return.

You’ll need to keep records of expenses for five years after you submit your return for that tax year in case HMRC ask you to produce them.

UK property income (SA105)

Income

Your income from property tax return

If you’re a landlord, you’ll be asked to enter the income from rented properties in two separate sections.

In the first section, you’ll need to enter the total income from all furnished holiday lettings in the UK. If you have any furnished holiday lettings in the European Economic Area, you’ll need to enter the total income from these on a separate page.

In the second section, enter the total rent and income from other properties.

Expenses

If you make money from renting out a property, you can claim expenses for:

  • rates, insurance and ground rent
  • property repairs and maintenance
  • loan interest and other financial costs
  • legal, management and other professional fees.

Capital Gains (SA108)

Income

Income you need to declare for Capital Gains Tax is called ‘disposal proceeds’.

You’ll need to fill in a separate ‘disposal proceeds’ total for:

  • residential property
  • non-residential property, and
  • shares and securities.

Expenses

On a Capital Gains Tax return, you can claim for ‘allowable costs’. These include:

  • the price paid to buy the asset in the first place
  • costs of any improvements (must be reflected in the asset when it’s sold*)
  • other costs in buying or selling the asset – such as Stamp Duty when buying a property.

*What this means is, the improvement still needs to be present when the asset is sold. For example, you can’t claim for a new carpet in a house if you remove the carpet before you sell the property.

It’s important to keep good records to make sure you don’t claim for the same thing twice. This is because you might be claiming expenses as part of your Self Assessment tax return for property in previous years.

For example, if you claimed for maintenance on a buy to let property in a previous tax year, you can’t claim for the same expense as part of your Capital Gains tax return when you sell the property.

Paying your Self Assessment tax bill

How do I pay my Self Assessment tax bill?

When you’ve submitted your Self Assessment tax return, you’ll be told how much tax and, if you’re self-employed, National Insurance contributions you’ll need to pay.

When do you need to pay?

The deadline for payment is 31 January.

Can I pay my tax bill in instalments?

Yes, you can make payments in instalments. But these are an advance on your next tax bill.

You can arrange for what’s called a budget payment plan through your online account and decide how much you want to pay each week or month. You can also choose to stop paying for up to six months.

The only restriction is that you must be up-to-date with your previous Self Assessment payments.

But you can’t use this to pay for a previous tax bill in instalments.

How do I pay my tax bill?

There are many ways to pay your Self Assessment tax bill. But the length of time depends on which method you choose.

If you’re making your payment close to the deadline day, choose one of the faster options to make sure you don’t get penalised.

The fastest ways to pay are:

  • online or telephone banking
  • Clearing House Automated Payment System (CHAPS)
  • debit or corporate credit card
  • in person at your bank or building society.

But you can arrange for a bank transfer, Direct Debit or send a cheque.

What if I miss the deadline?

If you miss the deadline to register, submit your return or pay your bill – you’ll get a penalty.

If you’re up to three months late filing or paying tax, there’s a penalty of £100. If it’s later than this, the penalty will be more. You can appeal.if you have a reasonable excuse.

What if I make a mistake?

You don’t need to fill in your Self Assessment tax return all in one go. So it’s a good idea to start early and take your time to avoid mistakes.

Before you submit it, you’ll be given the chance to check your return and correct any mistakes you’ve made.

If you realise you’ve made a mistake after you’ve submitted, you can still make changes until the filing deadline the year after. This means, for the tax return you submitted by 31 January 2021, you can make changes until 31 January 2022.

Payment on account

Unless your last Self Assessment tax bill was less than £1,000, or you’ve already paid more than 80% of all the tax you owe, you’ll be asked to make ‘payments on account’ towards your next tax bill.

‘Payments on account’ are made up of two payments, each one is half of your previous year’s tax bill. They’re due by 31 January and 31 July.

For example, if your tax bill for 2018/19 was £1,500 – during the 2019/20 tax year, you’ll make two payments on account of £750 each. When you submit your 2019/20 tax return, these two payments are deducted from your tax bill.

So, if your 2019/20 tax bill was £3,000, £1,500 (two payments on account) will be deducted. And you’ll have to pay £1,500 as a balancing payment, plus an extra £1,500 as your first payment on account for the 2020/21 tax year.

If your tax bill is less, HMRC will send you a refund. If you know your tax bill will be lower, you can contact HMRC and ask for a reduction on your payments on account.

Time to Pay service

If you have an outstanding payment, or are worried you might miss a future payment, call the HMRC Time to Pay helpline on 0300 200 3822.

To use the Time to Pay service, you must have a Self Assessment tax bill of between £32 and £30,000.

You must also have no outstanding tax returns, have any other debts or payments set up with HMRC.

If you’re not eligible under these requirements, you might still qualify for Time to Pay. But you’ll need to contact HMRC direct.

You’ll have to pay interest on any tax paid late, and this will be added to any outstanding balances from February 2021.

What if you can’t afford to pay your tax bill?

If you can’t afford to pay your tax bill, you need to contact HMRC as soon as possible by calling the Business Payment Support Service on 0300 200 3825. This line is for everyone, not just for businesses.

HRMC will look at:

  • how much you owe
  • your income
  • expenditure
  • assets
  • savings and investments.

They’ll then decide whether you’ll be given more time to pay.

If you don’t pay on time, it’s likely you’ll have to pay interest and penalty charges.

You might be offered more time to pay or offered the chance to pay in instalments.

Tax is a priority debt. So if you can’t, or are struggling to pay, your tax bill – you need to call the Business Payment Support Service on 0300 200 3835.

If you don’t and simply refuse to pay, HMRC will take enforcement action against you. This can include directly collecting what you owe through:

  • your earnings
  • your bank account
  • your pension, or
  • repossession, or a debt collection agency.

You could also be faced with court action, risk being made bankrupt or having your business closed down.

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impartial help for all your money and pension choices.
Whatever your circumstances or plans, move forward with MoneyHelper.

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Looking for us? Now, we’re MoneyHelper

MoneyHelper is the new, easy way to get clear, free,
impartial help for all your money and pension choices.
Whatever your circumstances or plans, move forward with MoneyHelper.

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