Question 1

What does porting a mortgage mean?

Accepted Answer

Porting means transferring your existing mortgage deal — including the interest rate and remaining fixed or tracker term — from one property to another when you move. Rather than redeeming your mortgage and taking a new product, you carry the existing terms across to the new purchase. The lender treats it as a new application on the new property: your income, credit file, and the property itself are all reassessed. If you pass the lender's current criteria and the property is suitable, the port is approved and you keep your existing rate. If you need to borrow more than your current outstanding balance, the additional amount is typically placed on a separate product at current market rates.

Question 2

Can I port my mortgage if I am self-employed or have complex income?

Accepted Answer

Yes, but the lender will fully reassess your affordability as if you were a new applicant. If your self-employed income has changed since your original application — typically measured via the last 2–3 years of SA302s — the lender will use your current income figures, not the ones that originally secured your deal. This can create problems if your income has dropped, your trading structure has changed (for example, sole trader to limited company), or you have taken on additional credit. Contractors assessed on day rate at origination will be reassessed on the same basis. The critical point: porting is not guaranteed; it is a re-application with a rate preservation component.

Question 3

What happens if I need to borrow more than my existing mortgage balance when porting?

Accepted Answer

Top-up borrowing — where you need more than your current outstanding balance for the new property — is common when moving to a higher-value home. The lender will split the borrowing: your existing balance is ported at the current fixed or tracker rate, and the additional amount is offered at current market rates on a new product. The two parts will often have different end dates and terms. Some lenders require both parts to run on the same repayment type; others are more flexible. Affordability is assessed on the total combined borrowing. If the additional amount pushes you outside the lender's income multiple or stress test, you may not be able to top up on the port, and a full remortgage to a different lender may be the only route.

Question 4

Do I pay early repayment charges if I port my mortgage?

Accepted Answer

Porting is specifically designed to avoid ERCs when you move house — that is the primary benefit. If you complete the sale and purchase simultaneously and the lender accepts the port, no ERC is triggered. However, timing is critical: if there is a gap between redeeming your mortgage on the sale and completing the purchase of the new property, most lenders charge the ERC on the redemption, then rebate it once the port completes within their allowed window (typically 30–90 days, depending on the lender). If the purchase falls through and the port is not used, the ERC may be charged in full. Always confirm the exact porting window with your lender before exchanging on either transaction.

Question 5

Can I port my mortgage if I am on maternity or parental leave?

Accepted Answer

Yes, but lenders must assess your returning salary rather than your current statutory or enhanced leave pay. You will need an employer letter confirming your return-to-work date and the salary you will be returning to. The challenge with porting on parental leave is that it combines reduced current income with full affordability reassessment — some lenders are stricter on this than others. If your current lender refuses the port because of parental leave income, you face a difficult choice: wait until you return to work and potentially incur an ERC if your fixed term expires, or switch lender and pay the ERC. A broker can identify which lenders will assess returning salary favourably during leave.

Question 6

What if my porting application is refused on the new property?

Accepted Answer

If your lender refuses the port — because your income no longer meets their criteria, the property fails their valuation requirements, or the LTV on the new purchase exceeds their policy — you will need to redeem the mortgage and take a new product elsewhere. This means the ERC on your existing deal is triggered. If you are within a fixed or tracker period, the ERC can be substantial — often 1–5% of the outstanding balance in the early years. Before exchanging on a new purchase, commission a Decision in Principle from your existing lender or use a broker to stress-test your porting eligibility informally to understand the risk. If there is doubt, factor the ERC into your costs before committing.

Porting a Mortgage FAQ