Porting Your Mortgage: How It Works When Moving Home

Porting Your Mortgage: How It Works When Moving Home

Porting a mortgage means moving your existing mortgage deal from your current home to a new property.

In simple terms, you sell your current home, buy a new one, and ask your lender to transfer your existing mortgage product across. This may allow you to keep your current interest rate and avoid, or reduce, early repayment charges.

Porting can be useful if you are moving home before your current fixed-rate, tracker or discounted mortgage deal has ended.

But porting is not automatic. Your lender still needs to approve the new application, reassess your affordability, and accept the new property as suitable security.

👉 If you are thinking about moving home while still tied into a mortgage deal, it is worth checking whether porting is possible before making firm plans.

What does porting a mortgage mean?

Porting allows you to transfer your existing mortgage deal to a new property.

That usually means you are trying to keep the same:

• interest rate
• product terms
• remaining deal period
• early repayment charge structure
• lender relationship

For example, if you are halfway through a five-year fixed-rate deal, porting may allow you to keep that deal when moving to a new home.

However, you are not simply moving the mortgage without checks. You still need to apply to the lender again.

The lender will assess:

• your income
• your outgoings
• your credit profile
• your affordability
• the new property
• the loan-to-value
• whether the mortgage remains suitable

So while the product may be portable, the application still has to pass.

Why do people port their mortgage?

People usually port a mortgage because they want to move home without losing a good existing deal.

This can matter if:

• your current interest rate is lower than today’s rates
• you are still within a fixed-rate period
• you would face early repayment charges if you redeemed the mortgage
• you want to avoid unnecessary costs when moving
• you are happy with your current lender
• you need to move before your mortgage deal ends

Early repayment charges can sometimes run into thousands of pounds. If porting avoids those charges, it can make a major difference to the cost of moving.

Porting can also be attractive if your existing mortgage rate is much better than the deals currently available.

Is every mortgage portable?

No, not every mortgage is portable.

Many modern fixed-rate, tracker and discounted mortgages include a porting feature, but you should never assume this applies automatically.

You need to check your:

• mortgage offer
• product terms
• lender conditions
• early repayment charge rules
• porting deadline
• mortgage account details

Even if your mortgage is portable, that does not guarantee the lender will approve the new mortgage application.

This is one of the biggest misunderstandings around porting.

A portable mortgage means the lender may allow the product to move. It does not mean they must approve the move regardless of your circumstances.

How does porting a mortgage work?

The process usually has several stages.

Step 1: Check whether your mortgage is portable

Before doing anything else, check whether your current mortgage product can be ported.

You can usually find this in your mortgage offer or by contacting your lender.

You should check:

• whether porting is allowed
• whether the full mortgage can be ported
• whether there are any time limits
• whether early repayment charges apply
• whether ERCs can be refunded after completion
• whether extra borrowing is allowed
• whether your new property type is acceptable

This should be done early, ideally before you commit to a new purchase.

Step 2: Sell your current property

When you sell your existing home, your current mortgage is usually repaid from the sale proceeds.

This can sound confusing because you are “porting” the mortgage, but technically the old mortgage account is usually redeemed and the deal is then transferred to the new property, subject to the lender’s process.

Timing matters.

If the sale and purchase complete on the same day, porting may be more straightforward. If there is a gap between selling and buying, your lender’s rules become very important.

Some lenders may allow a time window for porting after redemption. Others may not be as flexible.

Tracker Mortgage vs Variable Mortgage: What’s the Difference? | Find Me A Mortgage

Step 3: Apply to port the mortgage

You must make a new mortgage application with your existing lender.

The lender will usually reassess your circumstances as if you were applying again.

They may review:

• income
• employment
• self-employed accounts
• debts
• credit commitments
• childcare costs
• dependants
• bank statements
• credit history
• affordability
• deposit/equity
• the new property

This is not just a paperwork exercise.

Even though you already have a mortgage with that lender, they still need to check that the new mortgage is affordable and suitable.

what is a tracker mortgage ? 

Step 4: The lender assesses the new property

The new property must be acceptable security for the lender.

The lender may consider:

• property value
• construction type
• lease length, if leasehold
• condition
• location
• resaleability
• property type
• valuation result
• any unusual features

Porting can fail if the property does not meet the lender’s criteria, even if your income and credit profile are strong.

For example, some lenders may be more cautious with unusual construction, short leases, certain flats, properties with commercial elements, or homes needing significant work.

Remortgaging and Saving Money | Find Me A Mortgage

Step 5: Deal with extra borrowing if needed

If your new home costs more than your current one, you may need to borrow extra.

This is where porting can become more complicated.

The existing mortgage product may be ported, but any additional borrowing may need to be taken on a new product at current rates.

That can leave you with two mortgage parts:

• Part 1: your ported mortgage deal
• Part 2: the extra borrowing on a new rate

These parts may have different:

• interest rates
• product end dates
• early repayment charges
• monthly payments
• terms

This is not necessarily a problem, but it needs to be understood properly.

Example of porting with extra borrowing

Imagine you owe £180,000 on your current mortgage and are moving to a more expensive property.

Your existing deal is portable and has a low fixed rate.

You need a total mortgage of £230,000 for the new home.

The lender may allow:

• £180,000 to be ported on your existing deal
• £50,000 extra borrowing on a new product at today’s rate

This means your mortgage may be split into two parts.

That can save money if your original rate is low, but the extra borrowing may be more expensive than your current mortgage.

Can porting help you avoid early repayment charges?

Yes, porting can sometimes help you avoid early repayment charges.

This is one of the main reasons people consider it.

If you repay your mortgage during a fixed, tracker or discounted deal, your lender may charge an early repayment charge. Porting can reduce or avoid this if the lender allows the deal to be transferred to the new property.

However, this is not always simple.

Early repayment charges may still apply if:

• completion dates do not align
• you do not complete the new purchase within the lender’s allowed timeframe
• you borrow less than before
• only part of the mortgage is ported
• the porting application is declined
• the new property is not acceptable
• you switch lender instead
• you fail to meet the lender’s porting conditions

Some lenders may charge the ERC when your old mortgage is redeemed and then refund it after a successful port. Others may handle it differently.

This is why you need to check the exact rules before relying on porting.

Can you borrow less when porting?

You may be able to borrow less, but this can affect early repayment charges.

If you are reducing the mortgage balance, the lender may treat part of the old mortgage as being repaid rather than ported.

For example, if you currently owe £200,000 but only port £150,000 to the new property, the lender may apply an early repayment charge to the £50,000 difference.

The exact treatment depends on the lender and product terms.

This is especially important if you are downsizing or using savings to reduce your mortgage.

Can you borrow more when porting?

Yes, you may be able to borrow more when porting, but the extra borrowing is usually assessed separately.

The lender will check whether the total borrowing is affordable.

If accepted, the extra borrowing may be placed on a different product from your existing mortgage.

That means you could end up with multiple mortgage parts and different end dates.

This can make future remortgaging more awkward, because one part may finish before the other.

When can porting go wrong?

Porting can fail for several reasons.

Common problems include:

• your income has reduced
• your credit profile has worsened
• affordability rules have changed
• you now have more debt
• your employment situation has changed
• the new property does not meet lender criteria
• the valuation is lower than expected
• the loan-to-value is too high
• you need more borrowing than the lender will allow
• the sale and purchase timings do not work
• the lender no longer accepts your circumstances

This is why porting should not be treated as guaranteed.

You may have a portable mortgage product, but the lender still has to approve the new case.

What happens if porting is declined?

If your porting application is declined, you may need to look at other options.

These could include:

• applying to a different lender
• taking a new mortgage deal
• paying early repayment charges
• reducing the purchase price
• increasing your deposit
• changing the property
• waiting until your current deal ends
• reviewing affordability and credit issues

A decline can become expensive if you have already committed to a purchase, so it is better to check porting viability early.

Porting vs remortgaging: what is the difference?

Porting means keeping your current mortgage product and moving it to a new property with the same lender.

Remortgaging usually means replacing your existing mortgage with a new deal, either with your current lender or a different lender.

Porting can be useful if your current rate is attractive or ERCs are high.

Remortgaging may be better if new deals are competitive, your ERC is low, or your current lender will not support the move.

The cheapest option depends on the numbers.

How to compare porting and remortgaging

To compare properly, look at:

• your current interest rate
• how long your current deal has left
• the early repayment charge
• any ERC refund rules
• current mortgage rates
• product fees
• valuation fees
• legal costs
• extra borrowing rate
• whether you are moving to a more expensive property
• whether your lender will approve the new application
• how long you expect to keep the next mortgage

It is not enough to compare interest rates alone.

A lower rate elsewhere may not save money if you have a large ERC to pay. Equally, porting may not be the best option if your current lender is expensive for the extra borrowing.

Is porting always cheaper?

No, porting is not always cheaper.

It can be cheaper if:

• your current rate is low
• your ERC is high
• your lender approves the port
• extra borrowing is limited
• your new property is acceptable
• the timing works

But porting may be less attractive if:

• your current rate is no longer competitive
• your extra borrowing rate is high
• your lender’s criteria are restrictive
• your mortgage is split into awkward parts
• the ERC is small
• another lender offers a better overall deal

The right answer depends on the total cost, not just the idea of keeping your old rate.

Can you port a mortgage to a more expensive house?

Yes, you may be able to port a mortgage to a more expensive property.

However, if you need extra borrowing, the lender will reassess affordability and may offer the extra borrowing on a separate deal.

For example, your old mortgage rate may be ported on the original amount, but the additional borrowing may be priced at current rates.

This can still be worthwhile, especially if your existing rate is low, but the whole package needs to be checked.

Can you port a mortgage to a cheaper house?

Yes, but if you borrow less, you may face early repayment charges on the amount you do not port.

For example, if your current mortgage is £180,000 and you only need £140,000 on the new property, the lender may see £40,000 as being repaid early.

Depending on your lender’s rules, this could trigger an ERC on that portion.

This is a common issue when downsizing.

Can you port a mortgage if your circumstances have changed?

Possibly, but it depends on what has changed.

Porting may be harder if:

• your income has fallen
• you have changed jobs
• you are self-employed with lower profits
• you have taken on more debt
• your credit score has worsened
• you have had missed payments
• your household costs have increased
• you now have dependants
• your affordability is weaker

Remember, your lender is reassessing the application. They are not simply transferring the old mortgage without checking.

If your circumstances have improved, porting may be easier.

Mortgage Quote UK | Compare Mortgage Options | Find Me A Mortgage

Does porting require a credit check?

Usually, yes.

Because porting involves a new mortgage application, the lender will normally assess your credit profile again.

This may include a credit search, affordability checks and updated documentation.

If you have had credit issues since taking out the original mortgage, this could affect the decision.

How long does porting a mortgage take?

The timescale can vary depending on the lender, property chain, valuation, underwriting and legal process.

Porting should be started early because timing matters.

Delays can cause problems if:

• your sale and purchase complete on different dates
• your lender needs extra documents
• the valuation raises concerns
• your affordability is borderline
• the chain is moving quickly
• your ERC refund window is limited

The sooner you check the porting rules, the better.

Mortgage Quote UK | Compare Mortgage Options | Find Me A Mortgage

Common mistakes when porting a mortgage

Assuming porting is guaranteed

This is the biggest mistake.

A portable mortgage only means the product may be moved if the lender approves the new application.

Leaving it too late

Timing issues can create unnecessary costs, especially where early repayment charges are involved.

Ignoring extra borrowing costs

If the new home is more expensive, the extra borrowing may be on a different and higher rate.

Not checking the new property

The lender must accept the new property as security.

Forgetting affordability reassessment

Your lender can reassess your income, debts and outgoings.

Comparing rates but ignoring total cost

A lower rate elsewhere may not be cheaper after ERCs, fees and timing costs.

Why advice matters when porting

Porting combines moving home, mortgage strategy, lender criteria and timing.

A mortgage broker can help you compare:

• porting your existing deal
• remortgaging to a new lender
• product transfer options
• early repayment charges
• extra borrowing costs
• affordability
• lender criteria
• property suitability
• timing risks

This can help you avoid expensive surprises midway through a move.

👉 Get advice before porting your mortgage.

Realistic example

Imagine you have a fixed-rate mortgage with a remaining early repayment charge of £8,000.

Your mortgage is portable and your current interest rate is lower than many new deals.

You are moving to a more expensive home and need some additional borrowing.

If the lender approves the port, you may be able to:

• keep your existing low rate on the original mortgage balance
• avoid or recover the early repayment charge
• take the extra borrowing on a new product
• move home without fully losing your current deal

If you do not check porting properly, you could:

• pay an ERC unnecessarily
• choose the wrong timing
• assume approval is guaranteed
• discover too late that the new property does not fit lender criteria
• end up with a more expensive mortgage than expected

Same move. Very different outcome.

Questions to ask before porting your mortgage

Before relying on porting, ask:

• Is my current mortgage portable?
• How much is my early repayment charge?
• Will the lender refund the ERC if I port?
• Is there a deadline for completing the new purchase?
• Can I borrow more if needed?
• What rate applies to extra borrowing?
• What happens if I borrow less?
• Will the lender reassess affordability?
• Has my income or credit profile changed?
• Is the new property acceptable to the lender?
• Would remortgaging be cheaper overall?
• What happens if the sale and purchase do not complete together?

These questions should be answered before you commit to a move.

FAQs about porting a mortgage

What does porting a mortgage mean?

Porting a mortgage means transferring your existing mortgage deal to a new property, subject to lender approval.

Is porting a mortgage guaranteed?

No. Even if your mortgage is portable, your lender must approve the new application and the new property.

Can I port my mortgage to a more expensive property?

Possibly. If you need extra borrowing, the lender will assess affordability and may offer the additional borrowing on a separate product.

Can I port my mortgage to a cheaper property?

Possibly, but reducing the mortgage balance may trigger early repayment charges on the amount not ported.

Do I need to reapply when porting a mortgage?

Yes. Porting usually involves a new mortgage application with affordability checks, credit assessment and property valuation.

Can porting avoid early repayment charges?

It can sometimes help avoid or recover early repayment charges, but this depends on your lender’s rules and completion timing.

What happens if porting is declined?

You may need to consider a new mortgage, pay early repayment charges, change the purchase, increase your deposit or wait until your deal ends.

Is porting better than remortgaging?

Not always. Porting may be better if your current rate is low and ERCs are high. Remortgaging may be better if another deal is cheaper overall.

How long does porting a mortgage take?

Timescales vary depending on the lender, valuation, underwriting and conveyancing. It is best to start early.

Should I use a broker to port my mortgage?

A broker can help compare porting with remortgaging, check affordability, review ERCs and identify timing risks.

Bottom line

Porting your mortgage can be a smart way to move home while keeping your existing mortgage deal.

It may help you avoid early repayment charges, keep a lower interest rate and reduce disruption when moving.

But porting is not automatic.

Your lender still needs to approve the application, reassess affordability and accept the new property. Extra borrowing may be placed on a different rate, and timing mistakes can become expensive.

Done well, porting can save money. Done badly, it can cost thousands.

👉 Find out if porting your mortgage is the right move before committing to your next property.