Moving Home Mortgage Guide — Porting vs Switching UK
Moving home raises big mortgage questions. Learn whether to port your current deal, switch lender, or borrow more — and what each option costs.
Moving home is one of the biggest financial decisions you will make, and your mortgage is at the centre of it. Whether you are upsizing to a larger family home, downsizing after the children have left, or relocating for work, the mortgage you choose for your next property can save — or cost — you thousands of pounds over the coming years. Understanding the difference between porting your mortgage, switching to a new lender, or combining both is essential before you commit.
Many home movers assume they must stick with their current lender, but that is rarely the case. The UK mortgage market is highly competitive, and the deal you took out two or three years ago may no longer be the best available. At the same time, porting can be valuable if you are locked into a low fixed rate and want to avoid early repayment charges. The right choice depends on your remaining deal term, your loan-to-value ratio, and how much you need to borrow for the new property.
In this guide we walk through every option available to home movers in the UK: porting explained, when switching lender makes more sense, how to borrow more when moving up the ladder, the full breakdown of costs including stamp duty, and a step-by-step timeline from having your offer accepted to picking up the keys. Use our stamp duty calculator and borrowing calculator alongside this guide to put real numbers to your move.
Your mortgage options when moving home
When you sell your current property and buy a new one, you have three main mortgage routes: port your existing deal to the new property, take out a completely new mortgage with a different lender, or port your current deal and top up with additional borrowing. Each option has trade-offs around cost, flexibility, and the rate you end up paying.
The best route depends on where you are in your current deal, how much equity you have built up, and how much the new property costs relative to your outstanding balance. A whole-of-market broker can model all three scenarios side by side so you can see the monthly and lifetime cost of each.
When you sell your current property and buy a new one, you have three main mortgage routes: port your existing deal, take out a completely new mortgage, or port and top up with additional borrowing. Our moving home mortgages hub covers each route in detail.
The best option depends on where you are in your current deal, how much equity you have, and how much the new property costs relative to your outstanding balance. A whole-of-market broker can model all three scenarios so you can compare monthly and lifetime costs.
Port your mortgage
- Transfer your existing deal — rate, term, and balance — to the new property. Ideal if you are mid-way through a competitive fixed rate and want to avoid early repayment charges.
Switch to a new lender
- Pay off your current mortgage on sale and take a brand-new deal with a different lender. Best when your deal has ended, the market offers lower rates, or you need more flexible criteria.
Port and top up
- Keep your existing deal for the current balance and add a second portion with the same lender at a new rate. Useful when moving to a more expensive property and you want to avoid ERCs on the original balance.
Start planning early
Speak to a broker as soon as you begin your property search. Knowing your budget and mortgage options before you make an offer puts you in a much stronger negotiating position with sellers.
Porting your mortgage explained
Porting means transferring your current mortgage deal to a new property. Your interest rate, remaining deal term, and outstanding balance stay the same — the security simply moves from one property to another. Most major UK lenders allow porting, but it is not guaranteed and you will still need to pass their affordability and valuation checks on the new property.
Porting is most valuable when you are mid-way through a competitive fixed rate and early repayment charges would be significant. If you have two years left on a five-year fix at 3.8% and the best new deals are around 4.5%, keeping your existing rate saves you money every month.
Porting means transferring your current mortgage deal to a new property. Your interest rate, remaining deal term, and outstanding balance stay the same — the security simply moves from one property to another. For a full walkthrough, see our porting your mortgage guide.
Most major UK lenders allow porting, but it is not guaranteed. You will still need to pass affordability and valuation checks on the new property, so porting is effectively a new application assessed against the lender’s current criteria.
When porting works well vs when it does not
| Porting makes sense | Porting may not work |
|---|---|
| You are mid-way through a competitive fixed rate | Your deal is close to expiry (ERCs are low or zero) |
| Early repayment charges are significant (2–5% of balance) | Better rates are available on the open market |
| You are moving to a similar or lower-value property | You need to borrow substantially more than your current balance |
| Your lender’s current criteria still suit your circumstances | Your circumstances have changed and you no longer meet the lender’s criteria |
Porting is not automatic
Even though your lender may advertise porting as a feature, they will reassess your income, outgoings, and credit history against their current lending criteria. If your circumstances have changed — for example, you have become self-employed or taken on additional debt — you may not be approved to port.
Getting a new mortgage when you move
If your current deal is ending within the next few months, or the market is offering significantly lower rates than your existing mortgage, switching to a new lender is often the better option. You repay your old mortgage when the current property sells and take out a fresh deal on the new one, giving you access to the entire market rather than a single lender’s products.
Shopping the whole market is particularly important if your equity position has improved. A lower loan-to-value ratio unlocks better rate bands, and the savings over a two or five-year fix can be substantial. A broker searches 90+ lenders in minutes and can identify deals with free valuations, cashback, or fee-free options that offset any switching costs.
If your current deal is ending soon, or the market offers significantly lower rates than your existing mortgage, switching to a new lender is often the smarter move. You repay your old mortgage when the current property sells and take out a fresh deal on the new one.
Shopping the whole market is particularly important if your equity position has improved. A lower loan-to-value ratio unlocks better rate bands, and the savings over a two or five-year fix can be substantial.
Why switching could save you money
Borrowing more when moving up the ladder
Most home movers are buying a more expensive property, which means they need to borrow more than their current outstanding balance. Even after factoring in the equity released from the sale of your existing home, there is often a gap to bridge. Lenders assess this additional borrowing through a fresh affordability check, looking at your income, committed expenditure, and credit profile.
If you are porting, the additional borrowing sits on a separate sub-account with its own rate and term. If you are switching lender entirely, the full amount is assessed as one new mortgage. Either way, it is worth knowing your borrowing capacity before you start viewing properties so you can set a realistic budget.
Most home movers are buying a more expensive property, which means they need to borrow more than their current outstanding balance. Even after factoring in the equity released from the sale, there is often a gap. Our guide on how much you can borrow explains the key affordability rules lenders use.
If you are porting, the additional borrowing sits on a separate sub-account with its own rate and term. If you are switching lender entirely, the full amount is assessed as one new mortgage.
How to work out what you can afford
- 01
Calculate your equity
Subtract your outstanding mortgage balance from your current property’s market value. Use our LTV calculator for a quick estimate.
- 02
Estimate your deposit
Your equity from the sale, minus selling costs, becomes your deposit on the new property. A larger deposit means a lower LTV and better rates.
- 03
Check your borrowing capacity
Most lenders offer 4 to 4.5 times your household income. Use our borrowing calculator to see where you stand.
- 04
Add deposit and borrowing together
Your maximum purchase price is roughly your deposit plus your maximum borrowing. A broker can fine-tune this based on specific lender criteria.
Example: moving from a £300,000 to a £450,000 property
If you owe £180,000 on a property worth £300,000, you have £120,000 of equity. After selling costs of around £5,000, your deposit is £115,000. To buy at £450,000 you need a mortgage of £335,000 — giving you a 74% LTV, which sits within competitive rate bands.
Costs to budget for when moving home
Moving home involves more upfront costs than a remortgage, so it is important to budget carefully. Stamp duty land tax is usually the largest single expense, followed by estate agent fees on your sale, conveyancing costs on both properties, and any early repayment charges if you are leaving your current deal early.
Some costs are fixed, others are proportional to the property price, and a few are negotiable. Getting a clear picture of total costs early on helps you set a realistic purchase budget and avoid any unpleasant surprises close to completion.
Moving home involves more upfront costs than a remortgage, so it is important to budget carefully. Stamp duty is usually the largest single expense, followed by estate agent fees, conveyancing, and any early repayment charges.
Some costs are fixed, others are proportional to the property price, and a few are negotiable. Getting a clear picture early helps you set a realistic purchase budget.
Full cost breakdown for home movers
Property purchase costs
- Stamp duty (SDLT): varies by price band — use our [stamp duty calculator](/calculators/stamp-duty) for an instant estimate
- Conveyancing (buying side): £1,000–£2,000 including searches and Land Registry fees
- Survey or valuation: £250–£700 depending on the type (condition report, homebuyer, full structural)
- Mortgage arrangement fee: £500–£2,000 (can often be added to the loan)
Property sale costs
- Estate agent fees: typically 1–1.5% of the sale price plus VAT
- Conveyancing (selling side): £500–£1,000
- Early repayment charge: 1–5% of your outstanding balance if leaving a deal early
- Energy performance certificate (EPC): £60–£120 if yours has expired
Example costs on a £400,000 purchase
The moving home mortgage timeline
From having your offer accepted to picking up the keys, a typical home move takes eight to twelve weeks. The mortgage application itself is usually the quickest part — most lenders issue a formal offer within two to four weeks. The rest of the time is taken up by conveyancing searches, dealing with any chain, and coordinating an exchange and completion date.
Buying chain-free or from a new-build developer can speed things up considerably. If you are also selling, aligning both transactions is critical to avoid bridging finance or temporary accommodation costs.
From having your offer accepted to picking up the keys, a typical home move takes eight to twelve weeks. The mortgage application is usually the quickest part — most lenders issue a formal offer within two to four weeks. For tips on speeding up the process, see our guide to chain-free buying.
Buying chain-free or from a new-build developer can speed things up considerably. If you are also selling, aligning both transactions is critical to avoid bridging finance or temporary accommodation.
Step-by-step timeline
- 01
Weeks 1–2: Offer accepted and mortgage application
Your broker submits the mortgage application with supporting documents. The lender instructs a valuation on the new property, which is usually completed within a few days.
- 02
Weeks 2–4: Mortgage offer issued
The lender assesses your application, reviews the valuation, and issues a formal mortgage offer. Your solicitor receives a copy and begins the conveyancing process.
- 03
Weeks 4–8: Conveyancing and searches
Your solicitor carries out local authority searches, environmental checks, and title reviews. They raise enquiries with the seller’s solicitor and work through any issues that arise.
- 04
Weeks 8–10: Exchange of contracts
Once all searches are clear and both parties are satisfied, contracts are exchanged. This is the point at which the purchase becomes legally binding and a completion date is set.
- 05
Weeks 10–12: Completion and keys
On completion day the mortgage funds are released, the purchase price is paid, and you collect the keys. Your solicitor registers the new ownership with the Land Registry.
Getting your mortgage agreed in principle before you start viewing properties means you can move quickly when you find the right home — and sellers take your offer more seriously.
- Regulator
- FCA register
- Updated
- 24 February 2026
More guides
Browse all- Guide7 min read
Mortgage Overpayments — How They Save You Thousands
Discover how overpaying your mortgage — even by a small amount each month — can dramatically reduce your interest bill and shorten your term.
by Allan18 Feb 2026
- Guide8 min read
Right to Buy Mortgage Guide UK — Council Tenant to Homeowner
The Right to Buy scheme lets council tenants in England purchase their home at a significant discount. This guide covers eligibility, discount levels, mortgage options, and the full application process.
by Saha5 Feb 2026
- Guide9 min read
Mortgage Affordability — What Lenders Really Look At
UK lenders look far beyond your salary when deciding affordability. Understand income multiples, stress tests, outgoings, and credit checks so you can maximise your borrowing power.
by Komal20 Jan 2026
Moving home? Let’s find your best mortgage option
Our advisers compare deals from 90+ lenders and will tell you whether porting, switching, or a combination gives you the best outcome. We handle the paperwork and keep your move on track from application to completion.