Remortgaging a buy-to-let: how it works.

What a remortgage is

Replacing the mortgage on a property you already own with a new one, either with a new lender (a remortgage) or with your existing lender (a product transfer, or rate switch). You do it because your fixed or discounted deal is ending and the alternative is the lender's standard variable rate, which for buy-to-let is often 8% to 9% in 2026. You might also do it to borrow more, to change the term, or to move the property into a limited company.

How buy-to-let is different

• The rent decides the loan. Lenders test that the rent covers the interest with a margin, at a stressed rate. Your own income is secondary, and some lenders barely look at it. The sums.
• Interest-only is normal. Most buy-to-lets are interest-only. The capital is repaid when the property is sold or refinanced, and the monthly cost is lower. Interest-only vs repayment.
• Lower loan-to-value. 75% is the usual ceiling, a handful of lenders go to 80%, and the best rates are at 60% to 65%.
• Bigger fees. Arrangement fees of 2% to 3% of the loan are common, and some low-rate deals carry 5% or more. The fee is part of the price. Costs.
• Mostly unregulated. Ordinary buy-to-let lending is not regulated by the FCA, so there is less consumer protection than on your own home. Use a broker who is FCA-authorised anyway; the good ones are.
• Specialist lenders. A large part of the buy-to-let market only lends through brokers: the lenders who take limited companies, HMOs, portfolios and adverse credit.

The process, in order

1. Six months before the deal ends: start. Most lenders let you secure a new rate up to six months ahead, and a remortgage to a new lender takes four to eight weeks. Ask your current lender for its product transfer offer as a benchmark. Fixed rate ending.
2. Talk to a buy-to-let broker. They compare the product transfer against the whole market, with your rent, your ownership structure and your loan size in the calculation.
3. Decision in principle. The lender's indication that it will lend, based on a soft or hard credit search and the figures. A day or two.
4. Full application. With ID, proof of address, bank statements, the tenancy agreement, proof of rent, and, for a company, the company documents. The broker submits it.
5. Valuation. The lender values the property and confirms the rental figure, which is the one used for the affordability calculation. If the surveyor's rent is lower than yours, the loan can drop.
6. Offer. Usually valid for three to six months.
7. Legal work. Simpler than a purchase. Many remortgage deals include free legals or cashback towards them. If you are moving to a new lender the solicitor redeems the old mortgage and registers the new charge.
8. Completion. The new lender pays off the old one. Time it for the day after your current deal ends to avoid an early repayment charge.

What you will need

• Photo ID and proof of address.
• Three months' bank statements showing the rent arriving.
• The current tenancy agreement (AST in England and Wales, PRT in Scotland, private tenancy in Northern Ireland).
• Your current mortgage statement and a redemption figure.
• Proof of income: payslips, SA302s or accounts, even where the lender has no minimum.
• For a limited company: certificate of incorporation, SIC codes, a list of directors and shareholders, and often the company's bank statements.
• For a portfolio: a schedule of every property with value, mortgage, lender, rate and rent. Portfolio landlords.
• Safety certificates: gas safety, EICR, EPC. Lenders increasingly ask.

Have the tenancy agreement and the last three months of rent payments to hand before the broker calls. They are the two documents that stall more buy-to-let applications than anything else.

A note on the numbers. Rental cover ratios, stress rates, loan-to-value limits and fees are typical of the market at the time of writing (2026) and differ from lender to lender. Tax rules are for individuals and companies resident in the UK and change with each Budget. This is general information, not advice: a broker will tell you what applies to your property, and an accountant what applies to your tax.