Buy-to-let and property income on your CT600: rent, expenses and losses

1. Rental income is not the same as taxable property profit

Use the rental income belonging to the accounting period, not simply the cash received. Company landlords use accounting principles and a property business is normally separate from a trade. See HMRC PIM1020.

The wizard's Turnover field is for trading sales. Enter rent separately, without subtracting agent fees or other costs. Our gross-entry accounts combine trading sales and rent in their turnover line. The Corporation Tax return keeps trading turnover separate from the taxable property result. Do not enter the same rent in both current-year fields.

2. Buy-to-let companies and property SPVs

Gross rent

Financial data → Profit & loss → Property rental income

Enter rent before deducting expenses.

Letting expenses

Property income and expenses → Cost of raw materials and consumables / Staff costs / Depreciation and amounts written off assets / Other charges

Enter prepared category totals. Property-only companies use these rows for their operating costs. Other charges excludes separately entered donations.

Mixed-company expenses

Trading income and expenses and Property income and expenses

Enter your allocation once in the appropriate activity’s rows. Do not repeat company totals in both sections.

Property tax adjustments

Tax adjustments → Property tax treatment

Enter prepared property disallowables and qualifying intangible deductions. These adjust the costs already entered.

Calculated property tax base

Property taxable profit/(loss)

Calculated from your rent, expenses and property tax adjustments. Check this result before filing.

Previous-year accounts

Prior-year column beside each income or expense row

Use the comparative balances and totals. Keep donations separate from Other charges. A brought-forward tax loss is not a comparative expense.

If the company only lets property, go to Company Profile & Period and under What the company does choose Property only. On Financial Data, trading sales are then hidden, but expense rows remain available. Enter raw materials or consumables, staff costs, depreciation and Other charges where relevant. We assign operating costs and disallowable expenses to property without asking for a second allocation.

In gross entry, Other charges excludes charitable donations. Enter donations separately and we include them once in the accounts. Interest and capital allowances also have their own fields.

3. A company that both trades and lets property

On Company Profile & Period, under What the company does choose Both. Then, on Financial Data, use Trading income and expenses for sales and trading costs, and Property income and expensesfor rent and letting costs. Each has materials, staff costs, depreciation and Other charges. Do not enter the same cost in both sections. We combine the figures for the company's annual accounts.

For a £1,000 shared cost that you allocate 60% to trading and 40% to property, enter £600 in the trading row and £400 in the property row. There is no separate property-share question.

Use your allocation of shared costs. We do not ask for evidence or an allocation-method explanation. Check deductibility using HMRC's property expense guidance.

Enter property disallowable expenses and any qualifying property intangible amortisation or impairment deduction underProperty tax treatment. These are tax adjustments to costs already entered, not additional expenses. See HMRC's business-use guidance.

This cost allocation does not add support for splitting capital allowances between trading and property. Read capital allowances for landlords before entering a claim.

4. When your figures need an adjustment we do not offer

We calculate the property tax base from rent less property running costs, plus property disallowable expenses and less qualifying intangible amortisation or impairment. Separate property realisation credits and debits also adjust it. Capital allowances, balancing charges, interest and brought-forward losses have their own fields. There is no property tax base override.

If your prepared figures need a different adjustment, contact us before filing. We can identify the specific field needed. Do not change rent or expenses simply to force a different tax result. Examples that may need a separate adjustment include:

• Replacement of domestic items relief. Conditions and limits apply, including replacement rather than initial purchase. Read the full HMRC PIM3210 conditions.
• A premium for granting a lease of 50 years or less. The income charge depends on the effective lease duration. See HMRC PIM1205.
• Costs incurred before the letting business started. Relief depends on the commencement and expense conditions. See HMRC PIM2505.

Older net-only drafts: keep the net field or choose Enter gross rent and separate expenses. On upgrade, enter the actual rent and costs in the blank rows. We calculate the property tax base from those figures. The upgrade has no undo action. We cannot reconstruct gross rent from a net figure.

Amendments: if the original return used an entered property tax base, we show that figure as no longer used. Its help icon preserves the original tooltip wording, labelled as original help. The amendment uses the calculated property tax base. Check the corrected preview, CT600 and computation before approving it.

Accounts longer than 12 months: check both Corporation Tax returns. With figures entered once, rent and running costs follow the existing allocation by days. With separate figures, enter each return's rent and costs on its own CT600 tab. Each return uses its calculated property tax base.

5. Where mortgage interest goes

Enter company mortgage and loan interest in Interest payable. Do not deduct it again in rent or running costs. Company borrowing costs use the loan-relationship rules, not the personal-landlord rules. See HMRC PIM2052.

An unused borrowing deficit is not a property loss. Read about non-trading loan relationship deficits and brought-forward deficits.

6. Worked examples

These examples have no interest, donations, capital allowances or loss relief.

• Property only: £30,000 rent, £6,000 running costs and £500 disallowable costs give a £24,500 property tax base. Enter £30,000 rent and £6,000 expenses, not £24,000 net rent.
• Trading and property: £100,000 sales with £14,000 trading costs and £1,500 trading add-backs. Separately enter £30,000 rent, £6,000 property costs and £500 property add-backs. Trading profit before other adjustments is £87,500 and the property base is £24,500.
• A letting loss: £1,000 rent and £6,000 deductible property costs give a £5,000 loss. Keep rent positive and enter costs separately.
• Checking the calculated base: the mixed example gives £24,000 after property running costs. Adding back £500 of disallowable costs gives £24,500 before other reliefs.

7. Property losses and prior-year accounts

Enter unused property losses from earlier periods in Property losses brought forward. The engine applies the supported loss treatment and shows the remaining balance in the computation. A current-period loss box is not the same as the unused balance.

Enter previous-year trading turnover and rental income beside the corresponding current-year fields. The property expense rows also have their own comparatives. Previous-year donations are separate from Other charges and do not affect the current-year tax calculation.

Companies House often publishes only balance-sheet figures. We prefill what is available and you enter the rest. For a property-only company, prefilled company income and costs appear in the property fields. For a mixed company, divide any prefilled company totals between trading and property without duplicating them. If a prefilled Other charges total includes donations, split it before adding a separate donation comparative.

Changing What the company does on Company Profile & Period clears financial entries after a warning. We fetch available prior-year figures from Companies House again. You enter anything the published accounts do not contain.

8. Scope and official guidance

This route supports UK property within our micro-entity filing service. Overseas property and unsupported capital-allowance treatments need a different filing route. Selling an investment property is not rental income. See chargeable gains on property disposals.

You decide whether the company qualifies for the accounts format. Read about micro-entity thresholds and the two-year rule and associated companies.

This is general guidance, not a check of entitlement to a deduction. We use the figures and treatment you enter. Check the linked HMRC guidance or seek advice if you are unsure about an expense or allocation.

If a property purchase fell through, read about abortive acquisition costs and mortgage fees before classifying the loss.