Three-Line Accounts and Simplified Reporting Under Making Tax Digital
Last updated: February 2026
Three-line accounts are the simplest way to report your business or property income to HMRC. Instead of breaking expenses down into dozens of categories, you report just three figures: total income, total expenses, and net profit. Under Making Tax Digital for Income Tax Self Assessment, this simplified approach carries over to your quarterly updates, meaning each submission can be as straightforward as entering two numbers.
What three-line accounts are
Three-line accounts, sometimes called simplified accounts or the three-line account option on the Self Assessment tax return, reduce your annual reporting to three figures:
- Total turnover (your gross income for the period)
- Total allowable expenses (everything you can deduct, added together)
- Net profit (income minus expenses)
You do not need to tell HMRC how much you spent on travel versus office supplies versus insurance. The total is enough. HMRC introduced this option to reduce the reporting burden on smaller businesses and landlords whose affairs are straightforward. It remains available under MTD, and for many people it will be the natural way to complete their quarterly updates.
Who is eligible
To use three-line accounts, your annual turnover must be below the VAT registration threshold, which is currently £90,000 from 1 April 2024. This applies to both self-employed sole traders and landlords. If you have multiple income sources, the threshold applies to each business or property income source separately, not to your combined total.
Most people who fall within the MTD for Income Tax thresholds will also qualify for three-line accounts. The first MTD phase from 6 April 2026 covers those with qualifying income above £50,000, the second phase from 6 April 2027 covers income above £30,000, and the third from 6 April 2028 covers income of £20,000 or more. Since all of these sit below the £90,000 VAT threshold, the majority of people brought into MTD will be eligible to use simplified reporting if they choose.
How three-line accounts work for quarterly updates
Under MTD, you submit four quarterly updates to HMRC each tax year, plus a Final Declaration by 31 January. When using three-line accounts, each quarterly update contains just two figures: your total income for the quarter and your total expenses for the quarter. Your MTD-compatible software calculates the net profit automatically.
The quarterly deadlines remain the same regardless of which reporting method you use:
- Quarter 1 (6 April to 5 July): submit by 7 August
- Quarter 2 (6 July to 5 October): submit by 7 November
- Quarter 3 (6 October to 5 January): submit by 7 February
- Quarter 4 (6 January to 5 April): submit by 7 May
There is no requirement to categorise individual expenses into HMRC’s standard headings such as premises costs, repairs, travel, professional fees, or phone and internet. You simply add up everything you have spent that qualifies as an allowable business expense and enter the total. This makes record-keeping simpler, particularly for landlords whose main expenses tend to be a handful of recurring costs like mortgage interest, letting agent fees, and maintenance.
Interaction with cash basis
Most taxpayers eligible for three-line accounts will also be using the cash basis of accounting. Under cash basis, you record income when you receive it and expenses when you pay them, rather than when they are invoiced. There is no need to deal with debtors, creditors, or accruals.
The combination of cash basis and three-line accounts is the simplest possible reporting setup under MTD. You record money in and money out as it hits your bank account, then report the totals each quarter. For a landlord receiving rent by standing order and paying a handful of regular bills, this can be managed with a basic spreadsheet or the most straightforward MTD software on the market.
Joint property and three-line accounts
If you own property jointly with another person, HMRC allows you to report your share of the income and expenses. Three-line accounts can be combined with joint property reporting. Each co-owner reports their proportion of the total income and total expenses on their own quarterly updates. For a married couple who own a rental property 50/50, each person submits half the rent received and half the expenses paid.
This is straightforward in practice. One person typically manages the property records, and the figures are simply split at reporting time. Your software should allow you to record the full amounts and then apply your ownership percentage when generating the quarterly submission.
What happens if turnover exceeds £90,000
If your turnover crosses the £90,000 VAT threshold during the tax year, you lose eligibility for three-line accounts. You must then switch to full categorised reporting, breaking your expenses into HMRC’s standard categories for the entire year, not just from the point you exceeded the threshold. This means you need to have kept sufficient records to categorise your expenses retrospectively.
In practice, this is unlikely to catch many people by surprise. If your turnover is approaching £90,000, you should already be monitoring it closely because of the VAT registration requirement. Your accountant or software should flag when you are nearing the threshold. The safest approach for anyone with turnover above £70,000 is to keep categorised records from the start of the year, even if you intend to submit using three-line accounts. That way, switching to full reporting mid-year does not require going back through months of bank statements.
Three-line accounts vs full categorised reporting
| Feature | Three-line accounts | Full categorised reporting |
|---|---|---|
| Figures submitted per quarter | 2 (total income, total expenses) | Income plus 10+ expense categories |
| Eligibility | Turnover below £90,000 | Anyone (required above £90,000) |
| Record-keeping requirement | Must keep records, but only totals are reported | Must keep and report by category |
| Time to complete quarterly update | Minutes | Longer, depending on transaction volume |
| Visibility for tax planning | Limited (no expense breakdown visible to HMRC) | Full breakdown available |
| Accountant review | Harder to spot issues from totals alone | Easier to identify anomalies and advise |
| HMRC enquiry risk | May prompt more questions if queried | Detailed records can resolve queries faster |
Both approaches are equally valid, and HMRC does not penalise you for choosing three-line accounts. The difference is practical rather than legal: simplified reporting is faster but gives you and your advisers less granularity to work with.
Who benefits most
Three-line accounts suit landlords with simple property portfolios best. If you receive rent from one to three properties and your expenses are predictable (insurance, agent fees, minor repairs, mortgage interest), there is little to gain from categorising those costs each quarter. The total is what matters for your tax calculation, and HMRC already knows the broad picture from the income figure alone.
Small sole traders with low transaction volumes also benefit. A freelance tutor, a market stallholder, or someone running a small online shop with turnover under £50,000 and a handful of expense types can complete their quarterly updates in a few minutes using three-line accounts.
Conversely, three-line accounts are less suitable if you want your accountant to monitor your spending patterns, benchmark your costs against prior years, or identify areas where you might be over-spending. Categorised reporting gives both you and your adviser a clearer picture of where your money goes, which supports better tax planning and business decisions over time.
Limitations to be aware of
While three-line accounts reduce the reporting burden, they come with trade-offs. Your accountant cannot easily spot that your repair costs have doubled compared to last year, or that you are missing a deduction you previously claimed, if all they see is a single expense total each quarter. At year-end, you may still want a detailed breakdown for the Final Declaration, especially if you are claiming capital allowances or loss relief.
HMRC still requires you to keep the underlying records. Using three-line accounts does not mean you can throw away your receipts. If HMRC opens an enquiry, you will need to produce records showing what the expenses were and that they were allowable. The simplification is in reporting, not in record-keeping.
There is also the question of mortgage interest for landlords. Since the restriction on mortgage interest relief (limited to basic rate tax credit), this figure needs to be identified separately regardless of whether you use three-line accounts for your other expenses. Your software or accountant will need to handle this distinction at the Final Declaration stage.
Worked example: Aisha, landlord with three properties
Aisha owns three residential rental properties in Manchester with gross annual rent of £42,000. Her annual expenses include letting agent fees of £4,200, insurance of £1,800, repairs and maintenance of £2,400, and mortgage interest of £9,600. Her qualifying income puts her into the first MTD phase from April 2026.
For her Q1 quarterly update (6 April to 5 July), Aisha received £10,500 in rent and paid £2,100 in total expenses. Using three-line accounts, her software submission contains just those two figures: £10,500 income and £2,100 expenses. The quarterly update takes her five minutes.
She follows the same process for Q2, Q3, and Q4. Each quarter she enters total rent received and total expenses paid. Her accountant reviews the figures briefly each quarter to check they look reasonable, then handles the detailed breakdown at year-end for the Final Declaration. At that point, the accountant separates out the mortgage interest for the finance cost restriction, claims any capital allowances on furnishings, and ensures all reliefs are applied correctly.
This approach works well for Aisha because her quarterly reporting is fast and low-effort, while the complex tax work still gets proper attention at year-end from a professional. The quarterly updates give HMRC the running totals they need, and Aisha avoids spending time categorising every expense four times a year.
Getting set up
If you think three-line accounts are the right approach for your MTD submissions, the steps are straightforward. Choose MTD-compatible software that supports simplified reporting, ensure your digital records capture total income and total expenses each quarter, and submit by the deadline. Most software packages include a simplified reporting option alongside the full categorised view.
If you are unsure whether simplified reporting suits your circumstances, or if you want professional help with your quarterly submissions and year-end Final Declaration, our team at Jack Ross can advise. As a Xero Gold Partner, we set up and manage MTD-ready software for sole traders and landlords across Manchester and beyond. Get in touch to discuss your options before the April 2026 deadline.
