Let-to-Buy Calculator
Remortgage your current home onto a BTL to release equity, then buy your next home — all in one view.
Includes released equity + savings.
Letting out a £0 UK home releases £0 in equity toward a new purchase. Rent covers the BTL with £0 surplus per month; the new home mortgage costs £0/month.
How let-to-buy works
Two products, one completion
Most lenders require both the BTL remortgage on your current home and the residential mortgage on the new home to complete on the same day. This keeps the equity flowing straight from one to the other.
Watch the stamp duty surcharge
You'll own two homes after completion, so +5% SDLT applies on the new purchase in England & NI. If you sell the old one within 36 months, HMRC refunds the surcharge.
Frequently asked questions
What is a let-to-buy mortgage?
You remortgage your current home onto a buy-to-let product (keeping it as a rental), and take out a new residential mortgage on the property you're moving into. Two products, two applications, usually completing simultaneously.
How much equity can I release?
UK BTL lenders typically cap LTV at 75%. So on a £350k home with a £150k mortgage, you could remortgage to a £262,500 BTL — releasing £112,500 toward your new home purchase.
Do I pay extra stamp duty on the new home?
Yes — you'll own two properties after completion, so the new home attracts the +5% additional-property surcharge on SDLT (England & NI). Unless you sell the old home within 3 years, in which case you can reclaim the surcharge.
How much rent do I need?
Rent must cover the BTL mortgage at the lender's ICR (125–145%). See our BTL stress-test calculator. Most lenders also want 125% at a stress rate of ~5.5%, so rent needs to be about 7–9% of the BTL loan amount annualised.
Let-to-buy vs consent-to-let?
Consent-to-let is a temporary permission from your existing lender (often 6–12 months). Let-to-buy is a permanent switch to a BTL product. Use consent if the move is short-term, let-to-buy if it's permanent.
Reviewed by the Mortgage118 editorial team. Uses a 75% BTL LTV ceiling. Excludes legal fees, product fees and the ICR stress test. Provides an estimate only.