Selling and buying, without losing your footing.

Moving home usually means two transactions happening in sequence — a sale and a purchase — and a decision about what to do with the existing mortgage. The key questions to resolve before you list your current property:

• Porting your mortgage: most fixed-rate mortgages are portable, meaning you can move the existing rate and balance to the new property with the same lender. This avoids an early repayment charge (ERC) on the ported balance. However, porting is not guaranteed — the new property must meet the lender's criteria and you must pass a new affordability assessment even though the rate is staying the same. If you need to borrow more, the additional amount sits alongside the ported deal on a current rate.
• Early repayment charges: if you are within a fixed-rate period and cannot or choose not to port, an ERC applies to the balance being redeemed — typically 1–5% of the outstanding amount. In some cases the saving from switching to a lower rate on the new property outweighs the ERC. We model both options on a total-cost basis before recommending a route.
• Your equity as the deposit: the net proceeds from your sale (sale price minus outstanding mortgage and costs) become the deposit on your next property. The timing matters — you need the sale to complete before or at the same time as your purchase, which is why chain management is critical.
• New affordability assessment: even when porting, lenders re-run affordability at the point of the move. A change in income, a new credit commitment or a change in dependants since the original mortgage was taken out can affect how much the lender will confirm you can borrow. Knowing this before you agree a purchase price matters.
• Chain timing: the most common source of stress in a home move is chain delays. Starting your mortgage review early — ideally before your property goes on the market — means you have a confirmed position when you make an offer, and your solicitor is not chasing a mortgage decision while a chain collapses around it.
• Simultaneous exchange and completion: in a chain, all parties typically exchange contracts and complete on the same day. This requires all lenders, solicitors and parties to be ready simultaneously — which is why delays in one part of the chain affect everyone. Knowing your mortgage position early reduces your exposure to other parties' delays.

See our remortgage page if your existing deal is ending ahead of a move, or start your Mortgage Passport to get a confirmed position before you go to market.