Moving House With a Mortgage (2026): Port It, Replace It, or Time It
Your mortgage doesn’t move with the furniture — it either travels by application (porting), gets replaced by a new deal, or shapes when you move at all. The three routes, the money sequencing between sale and purchase, and the mid-fix maths nobody explains properly.
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Quick answer
When you move house, your mortgage takes one of three routes. Port it: most fixed and many other deals are portable — you carry your existing rate to the new home, usually without early repayment charges, but it’s a full new application (current criteria, new property, re-run affordability), and any extra borrowing for a bigger house is a separate top-up at today’s rates. Replace it: repay the old loan from your sale and take a brand-new mortgage — automatic if your deal’s ended, and sometimes worth doing mid-fix if today’s rates beat your old one by more than the early repayment charge costs. Or time it: plan the move around your fix ending and neither ERC nor porting constraints apply. The money side runs through your solicitor on completion day: sale price clears the old mortgage, the equity left over becomes the deposit on the purchase, and the new loan bridges the rest — so a £300,000 sale with £140,000 owing hands you £160,000 of deposit power (minus costs) for the next step. Yes, you can move mid-fix; yes, you can usually borrow more (affordability permitting); and no, none of it happens by default — every route is an application. Position as of July 2026.
Your home may be repossessed if you do not keep up repayments on your mortgage.
In this guide
What happens to your mortgage when you move house?
Nothing automatic — a mortgage is secured on a specific property, so moving means the loan must be repaid from the sale and re-established (in old or new form) against the new home. The three routes in full:
- Porting — your rate travels, your approval doesn’t. Portable products (most fixes) let you carry the existing rate, balance and terms to the new property, usually free of early repayment charges. The catch that surprises everyone: porting is a complete new application — today’s criteria, a valuation on the new home, your current income re-underwritten. Having the mortgage doesn’t guarantee keeping it; a dropped income or a quirky new property can sink a port. The mechanics live in our porting guide.
- A new mortgage — clean slate at market rates. The sale repays the old loan (plus any ERC if you’re mid-deal), and you shop the whole market for the purchase like any buyer — the obvious route when your deal has ended, when rates have fallen below your old fix, or when your current lender won’t stretch to the new numbers.
- The hybrid most bigger-house moves actually use: port the existing balance at the old rate plus a top-up loan at current rates for the extra borrowing — leaving you with two sub-accounts at two rates with two end-dates, which is workable but needs managing (misaligned fix-end dates are the classic future annoyance; a good broker aligns the top-up’s fix to the ported deal’s remaining term where possible).
Can you move house on a fixed-rate mortgage?
Yes — being mid-fix does not lock you in the house. Three exits, in order of typical cost: port the fix to the new property (no ERC on the moved balance — the designed-for-this route); break the fix — repay with the sale, pay the early repayment charge (typically 1–5% of the balance, tapering down as the fix ages), and take a new deal — worth real consideration late in a fix or when today’s rates beat your locked one; or wait for the fix-end and move unconstrained — often the right answer when the end is months away anyway (and the deal-end playbook is our fixed-rate ending guide). One timing trap worth naming: selling and repaying before completing a port can crystallise the ERC even if you buy again shortly after — lenders generally allow a gap of weeks-to-months for refund/port-completion, but the rules are product-specific, so anyone selling first and buying second should confirm the porting window before exchange. General fix mechanics: our fixed-rate guide.
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Port vs new deal: the real decision
| Port your deal | Take a new deal | |
|---|---|---|
| Your old rate | Keeps it on the existing balance | Gone — market rates apply |
| ERC | Usually none on the ported balance | Payable if mid-deal (tapered) |
| Extra borrowing | Top-up at today’s rates (two-rate structure) | One loan, one rate, one end-date |
| Approval | Full re-application at your current lender only | Whole market open — best-fit lender for today’s you |
| Wins when… | Your old rate beats today’s and your lender still suits you | Rates have fallen, your fix is nearly done, or your circumstances need a different lender |
The honest rule: porting is a comparison to run, not a loyalty reflex. When your locked rate is meaningfully below today’s market, porting is free money; when rates have drifted down toward or below your fix, the new-deal route (even ERC-paid, late in a taper) can win outright; and when your income or the new property doesn’t fit your current lender’s criteria, the whole-market route isn’t just better — it’s the only one open. Run both, every time — it’s a twenty-minute broker job against a five-figure consequence, and the timing framework is our remortgage timing guide’s home turf.
The money sequencing: sale → equity → purchase
How completion day actually works (illustrative)
You sell for £300,000 owing £140,000; you’re buying at £450,000. On completion day the solicitors run the waterfall: buyer’s funds arrive → your old mortgage (£140,000) is repaid → selling costs settle → the remaining ~£160,000 of equity transfers as your deposit on the purchase → your new £290,000 mortgage (ported, new, or port-plus-top-up) draws down → the sellers above you are paid, and the chain completes — usually all before mid-afternoon, with both moves on the same day precisely so nobody needs bridging finance. The equity number is the one to know early: sale price − mortgage balance − selling costs (~2–3%) = your real deposit, which sets your loan-to-value tier and therefore your rate on the next home. Budget the purchase side’s costs too — stamp duty (movers pay standard rates from £125,000), legals, survey, removals — via our buying costs guide, and expect the whole journey to run on the standard buying timeline with the chain as its main variable.
Borrowing more for the bigger house
Most moves trade up, so most mover mortgages are larger — and the extra borrowing is where movers rediscover that affordability is assessed fresh, at today’s rules, on today’s income. The strong mover position: years of clean payment history, real equity cutting the loan-to-value (a 35% deposit from equity buys the best rate tiers), and — often forgotten — the ability to extend the term on the new loan to hold payments steady while borrowing more. The re-run also catches people: incomes that dipped, new commitments (cars, childcare), or self-employment that’s changed shape since the original approval can all shrink the number — which is why the first act of any move, before the house-hunt hardens, is a fresh affordability check and a mover’s decision in principle. As for the monthly reality of the bigger number: our repayment tables show every amount from £100k–£400k at current rates — the ten-second answer to “what would £290,000 actually cost us?”
Timing the move: the fix-end sweet spot
If you have any control over timing, the cheapest move is the one that completes near your fix-end: no ERC, no porting constraints, the whole market open, and one clean new deal on the new house. Working backwards from that: mortgage offers last 3–6 months (purchase offers typically at the longer end), so applications can start roughly six months out; ERCs taper, so even missing the window narrowly costs less than breaking early; and chains rarely cooperate with anyone’s spreadsheet — which is why the port option exists as the pressure valve when the perfect house appears eighteen months into a five-year fix. The realistic hierarchy: time it if you can, port it if you can’t, break it only when the maths says so.
Special cases
- Moving somewhere cheaper (downsizing): porting works in reverse too, but reducing the balance below the ported amount can trigger a partial ERC on the repaid slice beyond your overpayment allowance — downsizers mid-fix should get that number before offering. Often the sale clears the mortgage entirely, making the purchase cash-or-small-loan and gloriously simple.
- Keeping the old home and buying the next: a different transaction entirely — converting the current mortgage to a rental basis while raising the new purchase from its equity — with its own products, stress tests and the additional-property surcharge; the whole structure is our let-to-buy guide.
- The new property itself can decide the route: lenders re-value and re-assess the house as well as you — non-standard construction, high-rise flats or anything unusual can pass at one lender and fail at your current one, turning a planned port into a whole-market search; our valuation guide covers what surveyors flag.
- Low or negative equity: a soft market can shrink the deposit the sale releases — if the numbers barely clear the balance, options narrow to higher-LTV new lending or waiting; get the redemption figure and a realistic sale price before committing to the onward purchase.
The bottom line
Moving with a mortgage is three decisions wearing one removal van: route (port the rate, replace it, or hybrid port-plus-top-up), money (equity out of the sale, loan-to-value into the purchase, affordability re-run at today’s rules), and timing (fix-end if you can, ERC maths if you can’t). None of it happens by default, all of it is an application, and the port-vs-new comparison alone is routinely worth thousands — run it, don’t assume it.
Movers are exactly who whole-of-market comparison serves best — real equity, bigger loans, and two routes to price against each other. Compare mortgage deals and get matched with a broker who runs mover cases daily — free, no obligation.
Moving house with a mortgage: FAQs
What happens to my mortgage when I move house?
It’s repaid from your sale and re-established against the new home — never transferred automatically. You either port it (carry your existing rate to the new property via a full re-application, usually without early repayment charges), replace it (new mortgage at market rates, with an ERC if you’re breaking a deal mid-term), or combine the two (port the balance, top up at current rates for extra borrowing). Your equity — sale price minus mortgage balance minus selling costs — transfers through the solicitors as the deposit on the purchase, all typically on one completion day.
Can you move house on a fixed-rate mortgage?
Yes — a fix doesn’t lock you in the property. Most fixed deals are portable, letting you move the rate to the new home ERC-free (subject to a full new application on current criteria); alternatively you can break the fix, pay the tapering early repayment charge and take a new deal — sometimes the cheaper route late in a fix or when rates have fallen; or time the move to complete near the fix-end and avoid the question entirely. If you’ll sell before you buy, confirm your lender’s porting window first, as repaying too far ahead of the new purchase can crystallise the charge.
Do I have to re-apply even if I’m porting my own mortgage?
Yes — this is porting’s least-understood feature. You’re carrying the rate, not the approval: the lender re-underwrites you on today’s criteria, re-checks income and commitments, and values the new property, and they can decline the port if anything no longer fits — reduced income, a new job shape, or a property type outside their appetite. It’s why movers should confirm portability and current eligibility before offering on the next house, and why a parallel whole-market option is the sensible plan B from day one.
Can I borrow more when I move house?
Usually, if affordability supports it — most trading-up moves do exactly this. The extra borrowing comes either as a top-up alongside a ported deal (at current rates, creating a two-rate structure) or within one new whole-market mortgage. Your strengths as a mover: equity cutting the loan-to-value into better rate tiers, payment history, and the option to extend the term to keep monthlies manageable. The re-run of affordability at today’s rules is the gatekeeper, so get a fresh borrowing figure before falling for a house that needs one you haven’t confirmed.
What if the house I’m buying is cheaper than the one I’m selling?
Downsizing simplifies the money — often the sale clears the mortgage entirely, funding the purchase outright or with a small new loan. The one trap sits mid-fix: porting a smaller balance means repaying the difference, and the repaid slice can attract a partial early repayment charge beyond your annual overpayment allowance. Get the exact figure from your lender before offering; sometimes adjusting the ported amount, the timing, or simply absorbing a modest charge is all it takes, but it should be a known number, not a completion-day surprise.
How long does moving house with a mortgage take?
The mortgage side rarely sets the pace: a mover’s application to offer runs the standard few weeks, offers stay valid 3–6 months (purchase offers typically at the longer end), and porting applications run on the same clock. The chain is the real timeline — sale and purchase completing simultaneously, coordinated by the solicitors, on the standard end-to-end buying timescale of roughly three to five months. The mover’s advantage is preparation: a decision in principle before listing, the redemption figure requested early, and the port-vs-new decision made before the chain starts asking for dates.
- Lender porting criteria and product terms — portability, ERC tapers and offer validity periods (2026)
- Conveyancing practice — chain completion mechanics and redemption sequencing
- Market guidance — port-versus-new-deal analysis and mover affordability treatment, 2026
Important information
nextmove is an introducer, not a lender or adviser. This article is for general information only and does not constitute financial advice. Portability, early repayment charges, offer validity, porting windows and affordability treatment vary significantly between lenders, products and individual circumstances and change over time — all figures are indicative as of July 2026 and should be confirmed against your own mortgage terms before you act. We introduce you to FCA-regulated mortgage brokers who can advise on your individual circumstances, and we may receive a fee or commission for doing so.
Your home may be repossessed if you do not keep up repayments on your mortgage.
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