Landlord tax return records for 2025/26: rent, repairs and mortgage costs.

1. Start with a property-by-property information pack

This guide focuses on individual landlords preparing a 2025/26 return, covering 6 April 2025 to 5 April 2026. List each property, the owners, ownership changes and letting dates. Keep tenancy agreements, agent statements, rent schedules, invoices and bank records together.

For each transaction, record the date, property, description, amount and supporting document. Mark private use, a purchase, sale or change of use for review. Do not simply divide a jointly owned property’s result in the way that produces the lowest tax: the ownership and reporting basis need checking.

2. Reconcile gross rent, deductions and bank transfers

Start with the agent’s gross rental statement, then identify fees, contractor costs and other deductions before reconciling the net amount paid into your bank. Include rents received directly as well as those collected through an agent. Record arrears, refunds and amounts retained from deposits separately for review.

Illustration: an agent records £1,500 rent and deducts £150 of fees before transferring £1,350. Recording only £1,350 as rent and then deducting £150 again understates the result. The schedule should explain the gross receipt, the fee and the transfer without counting either twice. This is a reconciliation example, not a ruling on every receipt or the timing basis.

3. Explain what repairs and refurbishment actually involved

Repair generally restores an existing asset, including replacement of subsidiary parts. An extension or a significant improvement is different. Modern materials do not automatically turn a repair into an improvement where the replacement is broadly equivalent.

Keep the contractor’s itemised bill, photographs and a short before-and-after description. A single invoice labelled “refurbishment” may include both repairs and capital work. A fair allocation needs evidence; the label alone does not decide deductibility. Work on a newly acquired property can require particular care where its condition and acquisition circumstances point to capital expenditure.

Keep domestic-item replacements separately from building work. Relief has its own conditions and does not normally cover the initial furnishing. Record what was replaced, the new item’s cost and any proceeds for the old item.

4. Separate mortgage interest, capital repayments and fees

Obtain the annual lender statement rather than using the total monthly payment. Identify interest, capital repayments and financing fees, and retain documents showing how borrowed funds were used. Mixed business and private borrowing needs separate review.

For an individual’s residential letting, qualifying finance costs are generally dealt with through a basic-rate tax reduction, not a deduction from rental profit. Limits can restrict relief and leave costs to carry forward. Companies have different rules. If a property was previously treated as a furnished holiday let, flag this: that special regime ended for Income Tax from 6 April 2025.

5. Understand why taxable profit and available cash differ

Illustration only: assume an individual’s ordinary UK residential letting has £18,000 rent, £3,000 allowable non-finance expenses, £6,000 qualifying interest and £2,400 capital repayments. Assume no losses or other adjustments.

• Rental profit before finance-cost tax relief: £15,000.
• Cash left after those expenses, interest and capital repayments, but before tax: £6,600.
• If the full £6,000 finance-cost amount qualifies for relief in that year, a 20% reduction would be £1,200.

This is not a final tax calculation. Other income, allowances and the statutory limits affect the outcome. The £2,400 loan repayment is not a rental deduction, and the £6,000 interest has not reduced the £15,000 profit. Keep the two calculations separate.

6. Keep annual records and long-term property evidence

HMRC’s landlord guidance says to retain records for at least five years after the 31 January return deadline. For an on-time 2025/26 return, that means at least 31 January 2032. Longer periods may be needed, including where enquiries or late filing are involved.

As a practical safeguard, retain purchase and sale completion statements, legal bills, ownership documents and evidence of capital works beyond the annual filing exercise. They may be needed to review a later disposal; keeping a cost does not establish that it will qualify for relief. See our property capital gains service before a sale or transfer.

7. Agree the next step before January

The normal online filing and payment deadline is 31 January 2027; check any specific HMRC notice. Send your adviser a list of missing items now, rather than an unexplained bank total shortly before filing.

UA Tax prepares landlord accounts and tax returns for clients in London and across the UK. Personal tax services start from £400, with the portfolio scope and fee agreed upfront. If you live abroad, use our non-resident landlord service; historic omissions may need a separate disclosure review. Get in touch with the number of properties, ownership structure and next deadline.

Official sources and further reading

These primary sources support the framework above. Check the current version before acting because tax law and HMRC guidance can change.

• HMRC: rental income records
• HMRC: rental income, record retention and domestic items
• HMRC PIM2025: repairs overview
• HMRC PIM2030: repairs and capital expenditure
• HMRC PIM2054: residential finance-cost restrictions
• HMRC PIM2058: calculating finance-cost relief
• HMRC: Self Assessment deadlines
• HMRC: 2025/26 Income Tax rates