Eight Days Left to File Your 2024-25 Self Assessment: What London Landlords Must Do Now

Why This Matters to London Landlords

The Self Assessment deadline for the 2024-25 tax year is 31 January 2026. Missing this date triggers an automatic £100 penalty, with escalating fines and interest if unpaid tax lingers. For London landlords—whether you manage a single property, an HMO, or a portfolio—the financial and operational risks are significant.

Beyond this immediate deadline, a new wave of tax compliance is arriving. From 6 April 2026, landlords with qualifying rental income exceeding £50,000 will enter the Making Tax Digital (MTD) for Income Tax regime. This means quarterly reporting of income and expenses rather than annual returns.

Immediate Risks: Penalties and Interest

If you have not yet filed your 2024-25 Self Assessment, act now. The £100 fine kicks in immediately after 31 January, regardless of tax owed. If you owe tax that is unpaid beyond the deadline, HMRC adds daily interest and further penalties:

• 1 February 2026: £100 fixed penalty
• After 3 months: Additional daily penalties of £10 per day, up to £900
• After 6 and 12 months: Further penalties of 5% of the tax due or £300 (whichever is greater)

These fines can quickly escalate, hitting landlords with substantial budgets and cash flow stress. For accidental landlords or smaller portfolios, this risk often catches people unprepared.

Preparing for Making Tax Digital Quarterly Reporting

From April 2026, if your qualifying income exceeds £50,000, HMRC requires you to submit quarterly updates using compatible digital software. This shift demands:

• Early selection and setup of MTD-compatible accounting software (free and paid options exist)
• Systematic record-keeping of incomes and allowable expenses throughout the year
• Scheduled quarterly submissions aligned with HMRC deadlines

Landlords renting multiple properties or managing HMOs will need particularly robust workflows to ensure accuracy and timeliness. Even those under the threshold should monitor their income closely to anticipate crossing it.

Capital Gains Tax Considerations

While the immediate urgency is on income tax filing and payments, landlords should stay alert to any changes in Capital Gains Tax (CGT) rates or rules announced this year, as these may affect disposals of rental properties. Consult your accountant early to review any planned sales or portfolio adjustments.

Practical Next Steps for Landlords

1. File Your 2024-25 Self Assessment Immediately: If you have not filed, complete your return now using the HMRC online system or through your accountant.

2. Settle Any Tax Due by 31 January 2026: Avoid penalties and interest by paying what you owe on time. Use HMRC’s digital payment options for ease.

3. Review Your Income Against the £50,000 Threshold: Check your qualifying income to see if MTD quarterly reporting will apply to you starting April 2026.

4. Choose and Set Up MTD-Compliant Software: Begin trialling accounting software now, ensuring your records are fully digital and ready for quarterly updates.

5. Schedule a Compliance Review: For portfolio landlords and property teams, arrange a session to align your workflows with upcoming MTD requirements.

6. Keep Secure Against HMRC Scams: Always verify communications through official HMRC channels. Never share personal or financial information via email or text.

Tailoring Actions by Landlord Profile

• Single-Property and Accidental Landlords: Prioritise filing and tax payment to avoid penalties. Consider consulting a tax advisor to evaluate if MTD applies.
• HMO and Portfolio Landlords: Implement digital accounting systems now. Train your property or finance teams on quarterly reporting demands.
• Letting Agents Managing Multiple Landlords: Support your clients by providing clear guidance on deadlines and MTD readiness.

How Rentals & Sales Can Support You

Our landlord intelligence hub offers tailored compliance audits, portfolio reviews, and pricing strategy consultations to help you navigate tax deadlines and digital transitions confidently. Schedule your session with our property tax specialists to minimise risk and optimise your operations.

Compliance Note: This article is for general guidance and does not constitute professional tax advice. Landlords should consult a qualified accountant or tax advisor regarding their specific circumstances.