HSBC has eased its residential mortgage treatment of buyers part-exchanging an existing home with a new-build developer. From 1 October, the arrangement counts as a financial incentive worth up to 2% of the new property's purchase price. Combined financial incentives of up to 5% can be accepted without an incentive-related reduction in the value used for loan-to-value calculations.
For a home mover, this could remove an obstacle in a transaction where the developer offers both part exchange and additional financial support. The benefit is not an automatic increase in borrowing. It is more room for the agreed package to fit the lender's rules without an adjustment that changes the mortgage calculation.
That makes this a useful criteria change rather than another rate announcement. A new-build purchase can look workable on income and deposit, yet become difficult once the lender assesses how the developer's incentives affect the property value used for lending.
What the New Treatment Means
Part exchange sits within the incentive allowance. It is not separate from the combined threshold.
Above the threshold, the excess is deducted. Mortgage Soup reports that financial incentives exceeding 5% require the amount above that level to be deducted from the purchase price for LTV purposes.
The independent valuation still matters. Acceptance of the incentives does not guarantee that the valuer will support the agreed purchase price.
Why Part Exchange Plus Incentives Could Previously Be a Problem
HSBC's earlier published criteria treated part exchange as a 5% financial incentive and did not permit additional financial incentives alongside it. That could rule out a package combining the developer's purchase of the existing home with another financial benefit.
The new treatment potentially allows combinations that were previously difficult under that policy. Where part exchange is attributed a 2% incentive value, another 3% of accepted financial incentives would bring the combined amount to 5%.
The practical opportunity is to review the complete transaction against the updated rules. It is not to assume that a previous mortgage assessment remains valid or that every incentive offered by a developer receives the same classification.
The 2% Figure Is Not the Value of Your Existing Home
The policy language can be easy to misread. It does not mean that HSBC recognises only 2% of the value of the property being sold to the developer. It concerns the lender's incentive treatment of the part-exchange arrangement, measured against the price of the new home.
The developer's agreed purchase price for the existing property remains a separate commercial figure. The amount available for the onward purchase then depends on the mortgage redemption balance, any charges and other transaction costs.
For example, a developer buying the existing home for £300,000 does not create a £300,000 deposit if £220,000 is required to repay its mortgage. The starting equity is £80,000 before any further costs. The incentive percentage must not be substituted for that actual sale-equity calculation.
The 5% Allowance Is Combined, Not Additional
A developer package should be considered as a whole. If the part-exchange treatment uses the full 2%, the remaining space within the combined threshold is 3%. It is not an extra 5% on top.
On an illustrative £600,000 new-build purchase, 2% is £12,000 and 3% is £18,000. Together they represent £30,000, or 5% of the purchase price. These figures describe the incentive assessment; the attributed part-exchange amount is not a separate cash payment to the buyer.
Any developer contribution must also be examined for how it is delivered. A payment towards a particular cost, a deposit contribution and an upgrade package can have different practical effects on the buyer's cash requirements. Their lender classification should be checked from the written terms.
| Illustrative £600,000 Purchase | Percentage | Amount Used in the Example |
|---|---|---|
| Assumed incentive treatment of part exchange | 2% | £12,000 |
| Additional accepted financial incentives | 3% | £18,000 |
| Combined financial incentives | 5% | £30,000 |
| Incentive-related deduction at this level | No excess above 5% | None, subject to the confirmed policy treatment |
A Value Deduction Can Change the Deposit Requirement
Loan-to-value compares the mortgage with the property value accepted for lending. If an incentive adjustment reduces that value, the same mortgage becomes a higher percentage of it.
Consider the same £600,000 purchase with a proposed £480,000 mortgage. With a lending value of £600,000, the LTV is 80%. Now assume the financial incentives total 7%, including the amount attributed to part exchange. The excess above 5% is 2%, or £12,000.
Deducting that excess gives an illustrative lending value of £588,000. The unchanged £480,000 mortgage would then represent approximately 81.63% LTV. If a hypothetical product or case limit were 80%, the maximum loan against that adjusted figure would be £470,400 — £9,600 below the original mortgage requirement.
That shortfall could require more buyer funds, a different eligible mortgage product or a revised package. The 80% limit here is an illustration, not a statement of HSBC's maximum lending for every new-build case.
| Illustrative Calculation | No Incentive Deduction | £12,000 Incentive Deduction |
|---|---|---|
| Purchase price | £600,000 | £600,000 |
| Value used in this LTV illustration | £600,000 | £588,000 |
| Proposed mortgage | £480,000 | £480,000 |
| Calculated LTV | 80% | Approximately 81.63% |
| Loan at a hypothetical 80% limit | £480,000 | £470,400 |
A Larger Incentive Does Not Automatically Produce a Better Funding Position
An additional benefit can reduce an expense while also affecting the lending calculation. Assess the cash benefit and any change in mortgage availability together before treating the package as an improvement.
Accepted Incentives Do Not Override the Valuation
The distinction between an incentive deduction and a market valuation is important. The lender may accept the package without making an incentive-related adjustment, while the independent valuation still comes in below the agreed price.
That can create a funding gap for a different reason. The buyer should therefore understand the outcome if the valuation supports the price and the outcome if it does not. Keeping the incentives within an accepted threshold does not remove the second possibility.
The property's specification, location, tenure, service or estate charges and suitability as security remain relevant. The buyer should assess those features alongside the developer's offer rather than using the incentive package as the main measure of value.
The Existing-Home Offer Still Needs Its Own Comparison
Part exchange can simplify the sale arrangements and help coordinate an onward purchase. Its commercial value depends on the price offered for the existing home, the certainty provided and the alternatives realistically available.
A buyer should compare the proposed part-exchange figure with an informed view of an open-market sale, including the costs, timing and uncertainty of that route. A generous-looking incentive on the new property may be offset by a less attractive offer for the current one.
The mortgage review needs the actual net equity available, not an estimated sale figure that has yet to be agreed. Any existing mortgage repayment charge should also be included, because it can change the funds left for the purchase.
Part Exchange Does Not Automatically Port Your Mortgage
A developer agreeing to buy the current home does not establish that its mortgage can move to the new property. Porting depends on the existing lender's process, the new security, the borrower's circumstances and any additional borrowing required.
The assessment should compare keeping an existing rate where possible with arranging a new mortgage, including the costs of redemption. If sale and purchase completion dates do not align, the lender's treatment of that timing also needs checking.
A buyer should not assume that part exchange resolves every funding dependency. The sale proceeds, mortgage redemption, deposit and new mortgage must work together on the actual completion timetable.
Put Every Incentive in Writing Before the Mortgage Assessment
The developer's written package should show the new property's agreed price, the offer for the existing home, each additional incentive and any conditions attached. That gives the adviser, lender and solicitor a consistent transaction to assess.
Non-cash benefits should also be disclosed. Their treatment cannot be inferred solely from the label used by the sales team. An incentive described as an upgrade, contribution or allowance needs enough detail for the appropriate classification to be established.
If the package changes after the mortgage application or offer, the change should be raised promptly. Adding another benefit late in the transaction may require the funding position to be reviewed, even if it appears favourable to the buyer.
What Buyers and Developers Should Establish Early
HSBC's Change Is a Reason to Reassess, Not to Choose the Lender Automatically
A more workable incentive policy can make a lender relevant to a case that previously did not fit. It still needs to be compared with the other available options on affordability, price, fees, property requirements and timing.
For developers and estate agents, the opportunity is to have the package checked before a buyer relies on it. For a buyer whose proposed arrangement was previously blocked by part-exchange treatment, a fresh assessment may identify a viable route.
There is no need to assume that every lender has changed its approach. The appropriate mortgage is the one that accepts the complete transaction and fits the borrower, with the costs and conditions understood.
How Willow Private Finance Can Help
Willow can review the developer's proposed package alongside the buyer's income, existing mortgage, available equity and purchase timetable. We can assess whether the incentives affect LTV, whether the expected deposit is sufficient and which lenders may accept the transaction.
That review can also compare porting with a new mortgage and identify the effect of a lower valuation or a change in incentives. The objective is a coherent funding plan before the buyer commits to deadlines that depend on mortgage approval.
Part Exchange Plus Incentives? Check the Mortgage Before Committing.
If a developer is buying your current home and offering additional contributions, have the whole package assessed together. HSBC's criteria change may improve the options, but valuation, equity and affordability still determine whether the purchase works.
Explore Residential Mortgage Options →Frequently Asked Questions
Understanding the updated part-exchange treatment and its practical mortgage implications.
What has HSBC changed for new-build part exchange?
From 1 October 2026, HSBC treats the part-exchange arrangement as a financial incentive worth up to 2% of the new property's purchase price. Combined financial incentives of up to 5%, including part exchange, can be accepted without an incentive-related reduction in the property value used for LTV.
Does the 2% figure mean HSBC only recognises 2% of my existing home's value?
No. It describes the incentive treatment of the part-exchange arrangement against the new property's price. The developer's agreed purchase price for your existing home and the equity available after repaying its mortgage are separate calculations.
Is the 5% allowance additional to part exchange?
No. It is the combined financial-incentive threshold, including the amount attributed to part exchange. If part exchange uses 2%, other financial incentives would need to stay within the remaining 3% to keep the combined amount at 5%.
What happens if total financial incentives exceed 5%?
The reported policy requires the amount above 5% to be deducted from the purchase price for LTV calculations. That can increase the calculated LTV or reduce the mortgage available at a particular LTV limit. The lender's valuation and other criteria still apply.
Does the criteria change guarantee HSBC will approve my mortgage?
No. Income, commitments, credit history, deposit, property valuation and the rest of the lender's criteria remain relevant. The complete incentive package must be disclosed and its treatment confirmed for the application.