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