When a broker or lender quotes you a monthly rate on a bridging loan, that figure is the starting point for understanding the cost, not the complete picture. Bridging interest can be structured in three different ways, each of which affects when you pay, how much you receive at drawdown, and what the final redemption figure will be. Added to the interest are arrangement fees, valuation costs, legal fees, and in some cases an exit charge. How all of these components interact depends on the structure chosen and how long the loan ultimately runs.

This guide walks through how bridging interest actually works, what each of the three interest structures means in practice, how the gross loan and net advance differ, and what a complete cost picture looks like before you commit to a facility. All figures used in examples throughout this article are illustrative only and should not be taken as a quote, offer, or guarantee. Actual rates and fees vary by lender, product, and individual circumstances.

Why bridging interest is quoted as a monthly rate

Standard mortgages are quoted as annual rates because they run for decades and annual figures give a meaningful basis for comparison over that timeframe. Bridging loans run for months, not years, which makes an annual rate a less intuitive way to express a cost that is being incurred month by month. A monthly rate is used because it maps directly to how the cost accumulates: each month the loan is outstanding, the agreed monthly rate is applied to the gross loan balance to produce that month’s interest charge.

The practical effect of quoting monthly is that rates can appear deceptively modest at first glance. A rate of 0.75% per month sounds small. Expressed as a simple annual equivalent by multiplying by twelve, it becomes 9% per year. On a gross loan of £300,000, 0.75% per month produces £2,250 in interest for every month the loan runs: £13,500 over six months, £27,000 over a full year. The monthly rate is accurate; it simply needs to be read in the context of the loan size and the expected term to understand what it means in cash terms. For regulated bridging products, lenders are required to disclose an annual percentage rate as part of their pre-contractual documentation. The APR on bridging facilities is often expressed as a high annual figure because it annualises both the interest and the upfront fees across a short term. This is not unusual or deceptive; it is simply a function of how APR is calculated, and it is one of several reasons why comparing bridging facilities on APR alone is less informative than looking at the total cost across the realistic term.

The three interest structures: rolled-up, retained, and serviced

How interest is paid on a bridging loan is a separate question from how much interest is charged. The three structures described below produce the same total interest cost over the same term at the same rate. What differs is when that interest is paid, how it affects the net advance at the start of the loan, and what the redemption figure looks like at the end. The examples below use consistent illustrative figures throughout: a gross loan of £300,000, a monthly rate of 0.75%, a term of six months, and an arrangement fee of 1.5% (£4,500). These figures are illustrative only.

Retained interest

With a retained interest structure, the lender calculates the full interest for the agreed term at the outset and deducts it from the gross loan, along with the arrangement fee, before paying out the net advance. Using the illustrative figures above: interest for six months at 0.75% per month on £300,000 is £13,500. The arrangement fee is £4,500. Both are deducted at drawdown, leaving a net advance of £282,000. No monthly interest payments are required. At the end of the term, the borrower repays the gross loan amount of £300,000, which settles the facility in full.

The advantage of retained interest is predictability. The net advance and the redemption figure are both fixed at the outset, and neither changes regardless of when during the term the loan is repaid. The limitation is that more is deducted upfront, reducing the net advance relative to the gross loan. If the loan is repaid early, some lenders will refund a proportion of the retained interest for the unused months; others will not. It is worth clarifying the early repayment terms before committing to a retained structure.

Rolled-up interest

With a rolled-up interest structure, interest accrues throughout the term but is not paid until the loan is redeemed. No monthly payments are required. Using the same illustrative figures: the arrangement fee of £4,500 is typically deducted at drawdown, giving a net advance of £295,500. Interest accrues at £2,250 per month. At the end of a six-month term, the borrower repays the gross loan of £300,000 plus all accrued interest of £13,500, for a total redemption of £313,500 (assuming the fee was deducted upfront; if added to redemption, the total would be £318,000 instead).

Rolled-up interest produces a higher net advance than retained interest because the interest is not deducted at drawdown. The trade-off is a higher redemption figure at the end. There is also a compounding consideration: some lenders apply simple interest on the original gross loan throughout the term, which produces a predictable accrual. Others apply interest on the growing balance, which means interest accruing on previously accrued interest. The difference becomes material on longer terms and larger loans. Confirming which basis applies before committing to a rolled-up structure is an important due diligence step. Our guide to gross versus net borrowing in bridging finance covers this distinction in more detail.

Serviced interest

With a serviced interest structure, the borrower pays interest monthly throughout the term, as they would with a standard mortgage. Using the illustrative figures: the monthly interest payment is £2,250 (£300,000 at 0.75%). The arrangement fee of £4,500 is deducted at drawdown, giving a net advance of £295,500. Over six months, total interest paid monthly is £13,500. At redemption, the borrower repays the gross loan of £300,000, bringing the total amount paid across the term to £313,500 in interest and principal, plus the arrangement fee already deducted at the start.

A serviced structure typically attracts a slightly lower monthly rate than rolled-up or retained, because the lender is receiving interest throughout the term rather than waiting until redemption. The practical requirement is cashflow: the borrower needs to be able to meet the monthly interest payments from available funds during a period when the underlying transaction may not yet be generating income. For borrowers who are between properties or who are managing a sale process during the bridging term, this can be a meaningful constraint. For borrowers who have sufficient liquidity to service the monthly payments comfortably, it can produce a lower total cost and a more straightforward redemption calculation.

The illustrative figures above use a £300,000 gross loan at 0.75% per month over six months with a 1.5% arrangement fee. Actual rates, fees, and structures vary by lender and individual circumstances. The table is intended to show how the same loan looks across three different structures, not to recommend one over another.

Gross loan and net advance: what you borrow versus what you receive

The gross loan is the total amount borrowed. The net advance is the amount that actually reaches your bank account or completes your purchase. The gap between the two depends on which interest structure is used and whether the arrangement fee is deducted at drawdown or added to the redemption figure. Understanding this distinction before the loan is arranged is essential, particularly if you need a specific sum to fund a purchase completion, because you may need to borrow more at the gross level than the amount you actually need to receive.

With a retained interest structure, the gap between gross loan and net advance is largest at the outset, because both the full term’s interest and the arrangement fee are deducted before drawdown. If you need £295,000 to complete a purchase, borrowing £300,000 at a retained interest rate of 0.75% for six months with a 1.5% arrangement fee will only deliver £282,000 as the net advance. You would need to borrow a higher gross amount, or fund part of the difference from savings, to ensure the net advance covers the required sum. With a rolled-up or serviced structure where only the arrangement fee is deducted at drawdown, the gap is smaller and the net advance calculation is more straightforward. Our guide to gross versus net borrowing in bridging finance explains the calculation across different structures in full. The practical implication for borrowers is always the same: ask the lender or broker to confirm the net advance figure explicitly before proceeding, and verify that it covers the funds required for completion.

What the total cost of a bridging facility actually consists of

The monthly interest rate is the most visible component of bridging cost, but it is not the only one. A complete cost picture requires adding several further items, some of which are paid at the outset, some during the term, and some at redemption. The components below are typical across the bridging market; availability, structure, and amounts vary by lender and product.

Upfront and deducted-at-drawdown costs

The arrangement fee is charged by the lender for setting up the facility and is typically expressed as a percentage of the gross loan, commonly in the range of 1% to 2%. On a £300,000 loan, a 1.5% arrangement fee is £4,500. It is usually deducted from the gross loan at drawdown, reducing the net advance, though some lenders allow it to be added to the redemption figure instead. The valuation fee covers the independent survey the lender commissions on the security property. The cost depends on the property type and value and the complexity of the instruction. For a straightforward residential property in a mainstream location, a valuation fee might range from a few hundred pounds to over a thousand; for a commercial property or a complex case, it can be considerably higher. Legal fees cover both the borrower’s solicitor and the lender’s solicitor. Bridging legal work tends to be more bespoke and faster-paced than standard conveyancing, which typically means higher fees per instruction. Budgeting at least £1,500 to £2,500 or more for the combined legal cost of a bridging transaction is sensible, though the actual figure depends on the property and any complications.

Ongoing and redemption costs

With a serviced structure, monthly interest payments are an ongoing cost throughout the term. With rolled-up or retained structures, no payments are made during the term, but the interest either accrues to the redemption figure (rolled-up) or has already been deducted at drawdown (retained). Some lenders also charge an exit fee at redemption, typically expressed as a percentage of the gross loan at the point of repayment, commonly in the range of 0.5% to 1%. Not all lenders charge an exit fee; it is worth confirming whether one applies before committing. A broker fee may also be payable, depending on the broker and whether their fee is included in the lender’s arrangement fee or charged separately. The full cost structure of a bridging facility, including the extension and default provisions that apply if the loan runs beyond the agreed term, is covered in detail in our guide to bridging loan fees explained.

How rate and term interact: an illustrative comparison

The two variables that most directly determine the interest cost of a bridging loan are the monthly rate and the length of time the loan runs. The table below shows how the total interest cost varies across three illustrative monthly rates and three terms on a gross loan of £300,000. These are interest-only figures and do not include arrangement fees, legal costs, or valuation fees. All figures are illustrative only.

Two patterns are immediately visible from this table. First, the difference between a 0.60% and a 0.90% monthly rate is modest over a short term but becomes more significant as the term extends. Second, and more consequential for most borrowers, the difference between a six-month loan and a twelve-month loan at the same rate is larger than the difference between any two rates at the same term. This is the core risk in open bridging loans where the exit timeline is uncertain: the rate is fixed at the outset, but the term is not, and term variation drives cost more than rate variation in most realistic scenarios.

The visual breakdown below illustrates how the same gross loan splits between net advance, retained interest, and arrangement fee across two different terms. All figures shown are illustrative only.

The visual makes the term effect concrete. The arrangement fee is the same in both scenarios because it is calculated on the gross loan, not the term. The retained interest doubles as the term doubles. The net advance shrinks accordingly. For a borrower who is planning around a specific net advance figure, the term selected has a direct impact on what they will actually receive.

What happens if the loan runs longer than the agreed term

Bridging loans have agreed terms, and when the exit does not complete within that term the loan does not simply continue on the same basis. What happens next depends on whether an extension has been agreed, whether the borrower is in default, and which interest structure was in place. Understanding this before taking out a facility is important, because the cost of an overrunning loan can escalate quickly.

Interest accumulation and the rolled-up structure

With a rolled-up interest structure, every additional month beyond the planned term adds another month’s interest to the redemption figure. If the lender charges interest on a compounding basis, the additional monthly interest is calculated on the growing balance rather than the original gross loan. The practical effect is that a loan which was planned as a six-month facility but runs for nine months does not cost 50% more in interest than the original plan. Depending on the rate, the compounding basis, and any extension fees, it could cost considerably more. For borrowers who are relying on sale proceeds to cover the redemption figure, a larger-than-expected redemption sum directly reduces the net equity released from the sale. Modelling what an extension would cost before the loan is arranged, rather than at the point when an extension is needed, is the most straightforward way to manage this risk.

Extensions, default rates, and refinancing

If the exit has not completed by the end of the agreed term, most lenders will consider granting an extension if approached before the term expires and if the exit plan remains credible. An extension typically carries an extension fee, continued interest at the agreed rate (or sometimes a revised rate), and in some cases a requirement for a new valuation of the security property. These costs should be factored into the decision to enter the facility in the first place: not as an expectation that an extension will be needed, but as a check that the deal remains viable if one is required.

If the loan enters default, the rate that applies is the default rate, which is typically significantly higher than the agreed monthly rate. Default rates of 2% per month or above are not uncommon in the bridging market. On a large loan, even a few months at a default rate can produce an interest bill that materially affects the overall transaction economics. Default also triggers a formal process with the lender that most borrowers would strongly prefer to avoid. The practical safeguard is straightforward: choose a term that includes a realistic buffer beyond the expected exit date, begin the extension conversation with the lender before the term expires rather than after, and understand the default provisions of the specific facility before signing. The downsizing bridge guide includes a calculator that shows how extended cost accumulates across different scenarios; the same principles apply to any bridging loan regardless of the specific use case. Adverse credit borrowers face particular exposure here: a narrower panel of lenders means fewer options if an extension is refused and refinancing to a new facility is the only route forward.

Frequently asked questions

Why is bridging interest quoted as a monthly rate rather than an annual one?

Bridging loans are short-term facilities, typically running for months rather than years. Quoting an annual rate for a product that most borrowers hold for three to twelve months gives a less intuitive picture of the actual cost than a monthly rate does. The monthly rate maps directly to how the cost accumulates: each month the loan is outstanding, one month’s interest is charged. A monthly rate of 0.75% on a £300,000 loan produces a specific, calculable figure of £2,250 per month that the borrower can work with directly when planning their costs.

That said, the monthly rate can make costs appear smaller than they are if read without context. Multiplying the monthly rate by twelve gives a simple annual equivalent, but the APR required to be disclosed on regulated bridging products annualises the full cost including fees, which often produces a considerably higher figure. Both figures are technically accurate; the monthly rate is more useful for calculating what a specific term will cost, while the APR provides a standardised comparison basis across products. Neither number alone gives the complete picture: the total cost across the realistic term, including all fees, is the most useful figure for evaluating whether a bridging facility makes financial sense for a specific transaction.

Which interest structure tends to suit most residential borrowers?

Rolled-up and retained interest structures are the most commonly used for residential bridging, primarily because neither requires monthly payments during the term. Residential bridging borrowers are often in the process of moving between properties: managing monthly interest payments on top of the ongoing costs of running and selling one property while settling into another is a practical constraint that many prefer to avoid. Both rolled-up and retained structures allow the interest cost to be settled from the sale proceeds at redemption, which keeps the monthly cashflow position cleaner during the bridging period.

Between the two no-payment structures, retained interest gives a lower and more predictable redemption figure, while rolled-up interest gives a higher net advance at drawdown. The choice between them depends on whether the priority is maximising the funds received upfront or certainty about what will need to be repaid. A serviced structure is less common in residential bridging but may suit borrowers who have reliable income during the bridging period, who prefer to reduce the redemption figure by paying interest as it accrues, and for whom a slightly lower monthly rate is worth the cashflow commitment. The right structure for any individual case depends on that borrower’s specific position, and a broker can model the different outcomes side by side.

Does rolled-up interest compound over the term?

It depends on the specific lender and product. Some bridging lenders apply simple interest on the original gross loan throughout the term: if the monthly rate is 0.75% and the gross loan is £300,000, the monthly interest charge is always £2,250 regardless of how many months have elapsed. The accrued total at the end of six months is simply £2,250 multiplied by six. Others apply interest on the growing balance, meaning that once interest has accrued it forms part of the balance on which the following month’s interest is calculated. Over a short term the difference between simple and compound interest is modest; over twelve months or more on a larger loan it becomes more significant.

This is one of the questions worth asking explicitly when comparing bridging products, particularly for longer terms. A lender who quotes 0.75% per month on a simple interest basis and a lender who quotes the same rate on a compounding basis will produce different redemption figures after twelve months. The illustration in a formal cost document should show whether the interest calculation is simple or compound, and the total amount payable at the end of the agreed term will reflect whichever method applies. If there is any ambiguity, asking for a worked example of the redemption figure at the end of the planned term, with the calculation shown, is the clearest way to confirm which basis is being used.

How does the arrangement fee interact with the net advance I receive?

The arrangement fee is almost always deducted from the gross loan at drawdown, which means it reduces the net advance directly. On a £300,000 gross loan with a 1.5% arrangement fee, £4,500 is deducted before anything else, so the starting point for the net advance calculation is £295,500. Any retained interest is then also deducted from this figure in a retained interest structure. The net advance is what remains after all drawdown-stage deductions.

The practical implication is that borrowers who need a specific net advance figure, for example to fund a purchase that requires a precise completion sum, need to factor the arrangement fee into the gross borrowing calculation. If you need £290,000 to reach your bank account, and the arrangement fee is 1.5%, the gross loan required is approximately £295,000 before any retained interest is also considered. Some lenders allow the arrangement fee to be added to the redemption figure rather than deducted at drawdown, which preserves the net advance but increases what must be repaid at the end. The approach varies by lender, and it is worth confirming which method applies to a specific product when comparing options. Always ask for the net advance figure in writing before proceeding.

How do I get an accurate total cost figure before I apply?

The most reliable way to get an accurate total cost figure is to ask the lender or broker for a full cost illustration that includes all components: the monthly interest across the full planned term, the arrangement fee, the valuation fee, an estimate of legal costs on both sides, any exit fee, and the total amount payable at redemption. For regulated bridging products, lenders are required to provide a European Standardised Information Sheet before the loan is entered into, which presents these figures in a standardised format. For unregulated products, requesting a written cost illustration in a similar format is the best approach.

It is also worth asking the broker or lender to model two scenarios side by side: the planned term, and a scenario with a realistic extension of two to three months beyond that. This gives a picture of what the total cost looks like if the exit takes slightly longer than expected, and it is one of the more useful pieces of information to have before committing to a facility. A broker who has access to multiple lenders can present these illustrations across several products simultaneously, which makes it much easier to compare total cost rather than headline rate alone. The bridging loan document checklist sets out what to have ready at application stage to ensure the process moves as quickly as possible once a suitable product has been identified.

This article is for informational purposes only and does not constitute financial advice. Your home or property may be repossessed if you do not keep up repayments on a bridging loan secured against it. All figures used in examples throughout this article are illustrative only and are not a quote, offer, or guarantee. Actual rates, fees, and structures vary by lender, product, and individual circumstances. Before committing to any bridging facility, request a full written cost illustration and seek independent advice if you are unsure whether the product is appropriate for your situation. Actual outcomes will depend on your individual circumstances.