The short answer
What happens to your mortgage when you move home?
When you move home, the existing mortgage is normally repaid from the sale and a mortgage is arranged against the new property. Your usable equity is the sale price after the mortgage redemption amount, other secured balances and sale costs have been deducted.12
You may be able to transfer an existing mortgage product, known as porting, but this is not automatic. The lender still assesses the application and new property, and borrowing more or less can change the product structure and early repayment charge treatment.15
A linked sale and purchase also creates timing risk. In England and Wales, an accepted offer is not legally binding until contracts are exchanged; Scotland and Northern Ireland follow different processes.34
Step 1 · Establish the sale equity
Start with net proceeds, not the expected sale price
The headline sale price is not the deposit for the next home. Obtain the redemption figure and allow for the costs that need to be paid from the sale before setting the onward budget.
Use a realistic figure rather than the most optimistic asking price.
Current balance, secured borrowing and any charge due at the sale date.
Estate agency, legal work, removals and other transaction costs.
The amount available for the next deposit before its purchase costs and reserve.
Before committing to the next home
Connect the sale, deposit and new mortgage
A change on either side of the move can alter the complete plan.- Rerun the figures if the sale price changes.
- Keep new purchase costs outside the deposit.
- Check the new payment against the life around the move.
Step 2 · Test the onward plan
When moving with a mortgage may be workable
A sound move works on the actual equity, complete purchase cost and an affordable mortgage route, with enough flexibility for the chain to change.
- Expected net sale proceeds and cash cover the new deposit and purchase costs.
- The new payment and continuing ownership costs remain affordable.
- Porting and replacing the mortgage have been compared using written figures.
- The property and timetable are acceptable in principle, subject to lender and legal checks.
Step 3 · Gather the current figures
Information worth preparing early
Current mortgage terms and a realistic sale estimate make the initial comparison more useful. If a figure is missing, an adviser can explain where to obtain it.
- Current mortgage statement and redemption figure
- Existing mortgage offer or product terms, including porting and ERC provisions
- Income, expenditure and credit-commitment evidence
- Estate-agent agreement and estimated sale costs
- Details of the current and proposed properties
Step 4 · Coordinate the chain
Keep the sale, purchase and mortgage moving together
- 01
Estimate net proceeds
Deduct the redemption figure, other secured balances and sale costs from a realistic expected sale price.
- 02
Set the onward budget
Add purchase and moving costs, then calculate the indicative borrowing needed for the new home.
- 03
Compare mortgage routes
Test porting with the current lender against replacing the mortgage, including fees, charges, term and features.
- 04
Coordinate the chain
Keep the lender, conveyancer and estate agent aligned on valuation, offer expiry, exchange and completion.
Confirm the net sale proceeds
Sale price less redemption, selling costs and moving costs.
Combine equity and borrowing
Keep purchase costs and a household reserve outside the deposit.
Align property, mortgage and timing
The lender and legal work must be ready for the same completion plan.
Recheck the move if the sale price, purchase price, mortgage or completion date changes.
Step 5 · Pressure-test the move
The details that can change the plan
Sale proceeds, lender terms and timing are connected. Recheck the plan whenever the price, property, borrowing or completion date changes.
Net equity
Use the redemption statement and realistic sale costs, not the headline sale price, to set the new deposit.
Porting terms
Check eligibility, timing, any borrowing increase or reduction and how an early repayment charge is handled.
New affordability
The lender reassesses income, expenditure, credit, loan-to-value and the proposed property.
Chain timing
Delays can affect exchange, completion, mortgage-offer validity, removals and temporary accommodation.
Illustrative move plan
Work from the redemption figure, not the asking price
A homeowner expects to sell for £325,000. They obtain the current mortgage redemption figure and list estate-agent, legal, removal and any early repayment costs before setting the budget for a £410,000 onward purchase.
- 1Compare a port with additional borrowing against a replacement mortgage.
- 2Record all fees, payments, product end dates and total amount payable.
- 3Rerun the figures if the sale price, completion timing or property changes.
Alternatives
Other routes to compare
Stay and adapt
Compare the cost and disruption of improving the current home with the full cost of selling and buying.
Change the onward purchase
A lower purchase price or different property can reduce additional borrowing and improve resilience.
Sell before buying
Temporary renting can remove the linked chain, but include rent, storage, double-moving costs and any porting time limit.
FAQs
Moving home questions
Possibly. This is usually called porting. It depends on the product terms, a new lender assessment and whether the new property is acceptable.
Sources
Sources used for this guide
- 1Selling a house or flat
MoneyHelper · Sale process, chains, ERC and exit-fee checks, porting questions and completion coordination.
- 2Mortgage fees and costs when buying or selling a home
MoneyHelper · Categories of sale, purchase, mortgage and moving costs.
- 3Buying a home
GOV.UK · The purchase sequence and offer status in England and Wales.
- 4Selling a home: offers and negotiations
GOV.UK · The non-binding status of offers before exchange in England and Wales.
- 5MCOB 11.6: Responsible lending and financing
Financial Conduct Authority · Affordability assessment for the new mortgage or additional borrowing.
Reviewed by Charles Frank Finance Limited on 31 July 2026. Lender criteria can change independently of this guide.