Only with the lender's agreement — and on most UK mortgages you do not have it. A standard residential mortgage prohibits letting without written consent, and a standard buy-to-let mortgage requires a tenancy of at least six months, which rules out nightly lets. The product built for it is a holiday-let mortgage: typically a 25% deposit, a rate around a point above buy-to-let, and lending assessed on projected letting income rather than a tenant's rent.
The detail
Letting on a residential mortgage without consent is a breach of the mortgage conditions, not a criminal matter, but the consequences are real: the lender can demand repayment, move you onto a higher rate, and your buildings insurance will not respond to a claim from a paying guest. Lenders' consent-to-let is designed for a homeowner who moves away and lets to a tenant; most refuse it for short lets outright, and the few that allow occasional holiday letting cap it at a set number of nights a year. Ask in writing and keep the answer.
Buy-to-let is no better. Almost every buy-to-let product requires the property to be let on an assured shorthold tenancy of six to twelve months to a single household, and short-term letting is an explicit exclusion in the terms. The reason is underwriting: the lender priced the loan against a tenant's monthly rent, not against occupancy risk. Being found out usually happens through the insurer after a claim, or through a licensing register in Scotland or a registration number in the EU that the lender can now check.
Holiday-let mortgages exist precisely to fill this gap and there are dozens of lenders in the market. The typical shape: maximum 75% loan-to-value, so a 25% deposit; a minimum personal income of around £25,000 outside the letting; and affordability tested on a letting agent's projection of low, mid and high season income, with the average weekly figure needing to cover the interest by 125% to 145%. Rates sit roughly a point above equivalent buy-to-let products, and most lenders want the property to be a house or a flat with no restrictive lease clause, in a location with a recognisable holiday market.
The numbers that matter
Where this stops holding
Lender criteria change monthly and differ between products more than the summary above can capture — the deposit, income floor and interest-cover figures are typical, not universal. This is a UK picture; lenders in other markets treat short lets differently, and none of it overrides local licensing rules, which apply whether or not the finance is in order.
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