Porting a Mortgage: Can You Take Your Mortgage With You When You Move?

If you are partway through a good fixed-rate deal and thinking about moving, one of the first questions worth asking is whether you can take that mortgage with you. The answer, in many cases, is yes. It is called porting, and when it is done properly it can save you thousands of pounds in early repayment charges. When it is done badly, or assumed rather than checked, it can derail a purchase at the worst possible moment.

At Drummonds Finance Group, we arrange porting mortgages regularly for clients across Oxford, Bicester and the wider UK, and we also see plenty of cases where porting looked like the obvious answer but turned out not to be. This guide explains how it actually works.

What porting actually means

Porting is the process of transferring your existing mortgage product, meaning your interest rate and its terms, from your current property to a new one. You are not literally moving the mortgage. Technically, you repay the old loan on completion of your sale and take out a new loan on the new property, but the lender applies your existing rate to it, and because you are staying on the same product, the early repayment charge is waived or refunded.

Most residential mortgages are portable, but portability is a feature of the product, not a right. Your mortgage offer or product terms will say whether your deal can be ported, and even where it can, the lender still has to agree at the time.

The part people miss: you have to reapply

This is the single biggest misunderstanding we come across. Porting is not automatic. The lender will underwrite you again, on their current criteria, as if you were a new applicant. Your income, outgoings, credit history and the new property all get assessed from scratch.

That matters because life changes. If you have gone self-employed since your original application, taken a new job, had children, taken on car finance, or your income has dropped, you may no longer fit the criteria you fitted two years ago. We regularly speak to moving home clients who assumed their existing lender would simply say yes, only to find the affordability assessment now falls short. Finding that out after you have offered on a house is stressful. Finding it out before you start viewing is just useful information.

Porting when you need to borrow more

Most people move to a more expensive property, which means porting alone is rarely the whole answer. The usual structure is that your existing balance moves across on your current rate, and the additional borrowing is taken as a top-up on one of the lender's current products. You end up with two parts to the mortgage, often with different rates and different end dates.

This is where the sums need doing properly. If your ported rate is excellent but the top-up rate is poor, the blended cost may not beat simply paying the early repayment charge and remortgaging the whole lot to a new lender at a competitive rate. There is no universal answer. It depends on the size of the ERC, the gap between rates, how long is left on your fix and how much extra you are borrowing. As a whole-of-market broker, we can run both scenarios side by side, and we do this comparison for clients week in, week out.

Take a simple illustration. Suppose you have £200,000 left on a fix at a rate well below today's market, with an early repayment charge of 3%, which is £6,000. Porting keeps the cheap rate on the £200,000 and adds, say, £100,000 of new borrowing at a current rate. The alternative is paying the £6,000 and putting the whole £300,000 on one new deal. Which wins depends entirely on the rate gap and the time remaining, and the answer flips as those numbers move. As a whole-of-market broker, we run both scenarios side by side for clients week in, week out, and you can get a feel for the repayment differences yourself using our mortgage calculator.

Porting when you are downsizing

Moving to a cheaper property and reducing the mortgage sounds simpler, but it has a catch. If you port only part of the balance and repay the rest, the lender will usually charge an early repayment charge on the portion you repay. Depending on the numbers, it can still work out well, but it needs checking rather than assuming. Downsizers also need to weigh the transaction costs of the move itself, including stamp duty on the new purchase, which we break down with worked examples in our guide to stamp duty in 2026.

When porting is not the right answer

Porting tends to make sense when your current rate is meaningfully better than anything available today, and your early repayment charge is large. It tends not to make sense when your existing deal has only a few months left, when today's rates are similar to or better than yours, or when your current lender's criteria no longer suit your circumstances.

If your fix is ending soon anyway, the porting question falls away, and the real decision becomes what to do at renewal, which we cover in our guide on whether to fix or take a tracker. And if you are staying with your current lender but not moving house, the comparison you want instead is a product transfer versus a full remortgage, which is a different calculation again.

Timing also matters. Most lenders require the sale and purchase to complete simultaneously or within a set window, commonly around 30 to 90 days, for the ERC to be refunded. If there is a gap between selling and buying, perhaps because you are breaking the chain or renting in between, you can lose the ability to port altogether, so tell your broker about any planned gap at the outset.

How the porting process works in practice

A ported application follows broadly the same path as a purchase mortgage. You get a decision in principle based on current criteria, offer on your new home, and submit a full application naming the product you want to port. The lender values the new property, underwrites your circumstances afresh, and issues an offer showing the ported portion and any top-up borrowing separately. Your solicitor then handles the redemption of the old loan and the completion of the new one, and the ERC is either not charged or refunded shortly after completion, depending on the lender's process. Start to finish, it fits the normal timescale of a purchase, but the earlier the eligibility check happens, the fewer surprises later.

Frequently asked questions

Can I port my mortgage to a more expensive house? Yes, and it is the most common scenario. You will usually need additional borrowing on a current product alongside the ported amount, subject to affordability.

Can my lender refuse to port? Yes. Portability makes the product transferable, but the application still has to pass current criteria on income, credit and the new property. Unusual construction types, flats above commercial units and other quirks can cause problems even when your finances are unchanged.

Do I pay the early repayment charge upfront? With some lenders, yes, refunded after the new completion within their porting window. Others simply do not charge it on simultaneous completions. Check the mechanics with your lender or ask us to.

Is porting worth it if my deal ends in six months? Usually not, because ERCs typically step down in the final year and current rates may be comparable. It is always worth pricing both routes before deciding.

How we help

Whether porting beats remortgaging is a numbers question, and it is exactly the kind of comparison a broker should do for you before you commit to anything. We will look at your current product terms, get an accurate early repayment charge figure, check whether you still fit your lender's criteria, and price the alternatives across the whole market. Sometimes the answer is to port. Sometimes it is to pay the charge and move on. Either way, you will know before you offer on a property rather than after.

If you are planning a move this year, get in touch or call us on 0330 1330034 and we will work through your options with you. Local to us? We work face-to-face and remotely with movers throughout Oxfordshire as well as nationally.

Your home may be repossessed if you do not keep up repayments on your mortgage.