Landlord Mortgage & Consent to Let Guide UK 2026

Using the wrong mortgage product for a rental property is one of the most common — and most serious — financial compliance errors landlords make. Letting a property on a standard residential mortgage without the lender's consent is a breach of the mortgage terms and conditions, which can result in the lender demanding immediate repayment of the full outstanding balance. This guide explains the distinction between residential and buy-to-let mortgages, how consent to let works, and what the Renters' Rights Act means for mortgaged landlords.

Residential mortgage vs buy-to-let mortgage

• Residential mortgage: Designed for owner-occupiers — the borrower lives in the property as their main residence. Letting without consent is a breach of the mortgage conditions
• Buy-to-let (BTL) mortgage: Designed for landlords — the property is let to tenants. Affordability is assessed on rental income (typically 125–145% of the monthly mortgage payment at the stress-test rate), not the borrower's personal income
• Consumer BTL mortgage: A small category of BTL mortgage for 'accidental landlords' (e.g. inherited a property or moved away from a former home) — regulated by the FCA like a residential mortgage
• Rate difference: BTL mortgage rates are typically higher than residential rates — factor this into your yield calculation before letting

Consent to let — for residential mortgage holders

• If you have a residential mortgage and want to let the property (e.g. moving abroad temporarily, moving in with a partner), you must obtain the lender's written consent to let before the tenancy begins
• Most lenders grant consent to let for a defined period (typically 12–24 months) — after which you must either obtain a new consent, switch to a BTL mortgage, or sell
• Lenders may charge a fee for consent to let (typically £50–£200) and may increase the interest rate while the consent is in place
• Apply in writing to your lender before signing the tenancy agreement — do not let the property and ask for retrospective consent
• Keep the consent letter on file — it may be required if the lender audits the property or if you need to evidence your compliance status

Renters' Rights Act impact on buy-to-let mortgages

• With Section 21 abolished, lenders can no longer rely on a 2-month accelerated possession route to recover a property from a non-paying tenant — the Section 8 process now takes 4–8 months
• Many BTL lenders are reviewing their criteria — some are increasing the ICR (interest coverage ratio) stress test rate or tightening eligibility for first-time landlords
• Rent guarantee insurance is more important than ever for mortgaged landlords — a 6-month possession process with no rental income while paying a BTL mortgage is a severe financial risk
• Ground 2 (mortgage lender seeking possession because the lender has been granted possession): this Section 8 ground allows a mortgagee to recover possession — 2 months' notice, mandatory
• Some lenders are introducing specific post-RRA clauses into BTL mortgage offers — check the special conditions of any new BTL mortgage carefully

Limited company buy-to-let

• Many landlords use a Special Purpose Vehicle (SPV) limited company for BTL investment — Section 24 tax changes (finance cost restriction) reduced the tax efficiency of individual ownership for higher-rate taxpayers
• Company BTL mortgages have their own criteria — typically higher rates than personal BTL, but interest remains fully deductible as a business expense
• The Renters' Rights Act applies to all private landlords in England regardless of corporate structure — a company-owned BTL property must comply with all the same obligations as an individually owned property
• Consider taking specialist tax and mortgage advice before switching from personal to company ownership — the SDLT costs and CGT implications of a transfer are significant