Buy-to-Let Remortgage FAQ
General information only. This is not financial advice.
Last reviewed: 2026-06-06
How does remortgaging a buy-to-let property differ from a residential remortgage?
Buy-to-let (BTL) remortgages are assessed primarily on the rental income the property generates rather than the landlord's personal income, unlike residential remortgages which focus on the borrower's salary or self-employed earnings. The key metric is the interest coverage ratio (ICR): the rent must cover the interest payment (at a stressed rate) by a minimum multiple — typically 125–145%, though some lenders require up to 160% for higher-rate taxpayers and limited company borrowers. This means that even if a landlord's personal income is strong, a BTL remortgage can be declined if the rent-to-mortgage payment ratio is insufficient. Additionally, BTL remortgages are assessed under the PRA's portfolio landlord rules for landlords with 4 or more mortgaged properties, which imposes stricter underwriting requirements across the whole portfolio.
What is the ICR stress test and how does it affect my BTL remortgage?
The ICR (interest coverage ratio) stress test requires the property's monthly rental income to exceed the mortgage interest payment at a stressed rate — typically 5–5.5% or the product rate plus a stress buffer — by a set multiple. For individual landlords paying income tax, the minimum ICR is usually 125% of the stressed payment. For higher-rate or additional-rate taxpayers (who cannot offset all mortgage interest against rental income due to Section 24), many lenders require 140–145% ICR. For limited company landlords, the ICR requirement may be 125% since the company pays corporation tax rather than personal income tax on rental profits. The practical effect is that a property with lower rent relative to its value — or one that has reduced occupancy — may generate insufficient rental income to meet the ICR at current rates, which can make remortgaging to a new lender difficult. Your existing lender may offer a product transfer on simpler terms.
Does remortgaging my BTL property count as a new application under portfolio landlord rules?
Yes — remortgaging a buy-to-let property, even to a new product with the same lender (except a straight product transfer), is typically treated as a new application and assessed under the PRA's portfolio landlord rules if you have 4 or more mortgaged buy-to-let properties. Portfolio landlord underwriting requires lenders to assess not just the property being remortgaged but the performance of the entire portfolio. This means providing a portfolio spreadsheet showing all properties, their rental income, mortgage balances, lenders, and rates. Some lenders use a simplified process for remortgages where the applicant is an existing customer with no change to borrowing — but this varies. First-time remortgagers from a lender with strict portfolio criteria can find the process more intensive than their original purchase mortgage.
Can I remortgage a BTL property held in a limited company?
Yes — limited company buy-to-let remortgages are available from a growing number of lenders, though the product range remains smaller than personal name BTL. The company must typically be a Special Purpose Vehicle (SPV) with an appropriate SIC code (68100 or 68209 for property investment), though some lenders also accept trading companies that own property. The assessment focuses on the rental income ICR within the company, and the individual directors are usually required to provide personal guarantees. Remortgaging a limited company BTL can be complicated by company mortgage history, existing charges on the company's property, and whether the lender is comfortable with the company structure. Lenders who specialise in limited company BTL mortgages and understand SPV structures tend to handle these remortgages most efficiently.
Can I remortgage a BTL property with sitting tenants?
Yes — having sitting tenants in place does not prevent remortgaging, and most BTL lenders actively prefer properties with tenants as they demonstrate genuine lettable income. The lender will ask for the current tenancy agreement (AST) to confirm the rent, tenancy length, and that it is on standard terms. Month-to-month tenancies (rolling periodic tenancies) are accepted by most lenders. Some lenders have restrictions on certain tenancy types — for example, some do not accept HMO tenancies, section 8 notices in progress, or rent-to-rent arrangements on standard BTL products (these require specialist lending). Where a tenant is about to leave and the property will be vacant during the remortgage process, some lenders require confirmation of re-letting intention or a new tenancy agreement before completion.
When should I start thinking about remortgaging my BTL property?
The standard advice is to start 3–6 months before your current BTL mortgage deal expires. BTL remortgages can take longer than residential remortgages to process — particularly for portfolio landlords — and starting early gives you time to compare lenders, gather documentation, and manage any complications without being pushed onto your lender's revert rate (standard variable rate), which is typically significantly higher than a new deal rate. If you have a fixed-rate BTL mortgage and rates have risen since you took it out, early remortgage planning is especially important: products can be reserved up to 6 months in advance with many lenders, locking in a rate before expiry. For portfolio landlords, allowing more time (6–9 months) is sensible given the additional documentation and underwriting review required.
Risk warning
Your buy-to-let property may be repossessed if you do not keep up repayments on your mortgage. Buy-to-let is not regulated by the FCA in the same way as residential mortgages. Rental income may fall and periods of vacancy will affect your ability to service the mortgage.
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