Bridging Loan Delay Calculator

The planned term on a bridging loan is rarely the actual term. Sales take longer than expected, refinance applications encounter queries, works overrun, and the exit that was due at month 9 lands at month 11. Each additional month costs money, and in many cases the cost per month during an extension is higher than during the original term because the rate may increase and extension fees apply on top. Knowing what a delay costs before agreeing the original facility is how well-structured deals avoid becoming financially strained ones.

This tool models the full cost of a bridging extension: the additional interest at a potentially higher rate, the extension fees charged per month, and the daily cost of the facility during both the planned term and the extension period. All figures are illustrative and the tool does not constitute financial advice.

About this tool

How to use the delay calculator

The tool is most useful when the borrower has a specific facility in mind and wants to stress-test the exit timeline. The default values show a common scenario where a 9-month bridge extends by 3 months at a higher rate with extension fees, which is a realistic modelling exercise for any refurbishment or sale-exit deal.

Extension rate and fee mechanics

When a bridging loan runs beyond the agreed term, the lender is exposed to the facility for longer than planned. Most lenders manage this by offering a formal extension, typically month by month, at terms that are less favourable than the original facility. The two most common additional costs are a higher monthly interest rate and a per-month extension fee. Both are applied on top of the ongoing interest that continues to accrue on the balance.

The rate uplift during an extension varies by lender but 0.25% or more above the original rate is typical, though the exact uplift depends on the individual lender and the facility terms. On a £300,000 facility, a 0.25% uplift adds £750 per month of extension in additional interest. The extension fee is typically calculated as a percentage of the gross loan (commonly 1%), charged for each month of extension. On a £300,000 loan, that is £3,000 per extension month. Together, a single month of extension on this facility could cost approximately £3,750 above what each month during the planned term cost. The extensions vs refinancing guide covers the decision between extending and finding an alternative exit when the original plan does not land on time.

Extension terms and the borrower’s protections differ depending on whether the facility is regulated or unregulated. Regulated facilities secured against the borrower’s residence carry FCA protections including access to the Financial Ombudsman Service, while unregulated facilities (the majority of UK bridging) offer greater flexibility but fewer consumer safeguards. Formal extensions may also involve additional professional costs beyond the interest and fees modelled by the tool, including the lender’s legal fees and a revaluation of the security property.

The daily cost of delay

Bridging loans are priced monthly, but delays are measured in days and weeks. A refurbishment project that overruns by two weeks, a sale that is delayed by a solicitor’s holiday, a refinance valuation that takes an extra week to book: these are all real-world scenarios where the cost is incurred in days, not months. The daily cost figure translates the monthly pricing into the metric that matters for project management and completion planning.

During the extension period, the daily cost is typically higher than during the planned term because the extension rate may be higher and extension fees add a fixed cost per month. A facility that costs £80 per day during the planned term might cost £160 per day during an extension once the rate uplift and fees are included. Knowing both figures before agreeing the facility allows the borrower to build realistic contingency into the project budget rather than discovering the daily cost of delay at the point when it is already being incurred. The common causes of refurbishment delay guide covers the practical factors that most frequently push exits beyond the planned term.

Building a buffer into the original term

The most effective way to avoid extension costs is to set a realistic original term. A term that covers the exit timeline plus one to two months of buffer ensures that a modest delay does not trigger extension fees and rate increases. The cost of the buffer months is the additional retained interest deducted (for retained structures) or the additional compounding on the balance (for rolled-up structures). In most cases, this is materially cheaper than the equivalent extension cost.

The tool quantifies this trade-off directly. The planned cost column shows the total cost at the chosen term, including any buffer months. The extension column shows what happens if the buffer is not sufficient and an extension is needed. Comparing the two makes the insurance value of the buffer visible. The early exit modeller complements this by showing the cost saving if the exit comes earlier than the buffered term, which quantifies the upside of the buffer: if it is not needed, the borrower exits early and pays less.

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Frequently asked questions

Do all bridging lenders offer extensions, or can they refuse?

Lenders are not obligated to offer an extension, and extension is always at the lender’s discretion. Most will consider one if the borrower communicates proactively, the exit strategy remains credible, and the LTV position has not deteriorated. A borrower who approaches the lender with evidence of a delayed but realistic exit, such as a sale agreed but not yet completed or a refinance application in progress, is in a much stronger position than one who simply runs out of term with no plan. Some loan agreements include pre-agreed extension terms, which provide certainty about the cost and availability of an extension before it is needed. If the facility is supported by personal guarantees, the borrower should check whether an extension alters the terms or scope of those guarantees.

If a lender declines to extend, the borrower may need to refinance the bridge with another lender (a “re-bridge”), which involves its own arrangement fees, legal costs, and a potentially higher rate. If refinancing is also not possible, the lender may appoint a receiver or seek possession of the security property. The cost of a re-bridge is typically significantly higher than a formal extension, which is another reason to choose the original term with a realistic buffer rather than the minimum possible duration.

What is a typical extension fee in the UK bridging market?

Extension fees commonly range from 0.5% to 1.0% of the gross loan per month of extension, with 1% being the most frequently quoted figure. On a £300,000 gross loan, a 1% extension fee is £3,000 per month. This is charged in addition to the ongoing interest, not instead of it. Some lenders charge a flat fee per extension rather than a percentage, and a small number include extension terms in the original offer without additional fees (though typically at a higher rate). Confirming the extension terms before agreeing the facility is one of the most important questions to ask during the quote comparison stage.

The bridging loan fees guide covers extension fees alongside the full cost structure including arrangement fees, exit fees, and other charges.

Why is the daily cost higher during the extension than during the planned term?

Two factors typically combine to make the extension period more expensive per day. First, many lenders charge a higher monthly rate during extensions, often 0.25% or more above the original rate, reflecting the increased risk of a facility that has not exited as planned. Second, extension fees add a fixed cost per month on top of the ongoing interest. The daily cost during the planned term includes only the interest and the amortised arrangement fee. The daily cost during the extension includes those plus the rate uplift and the extension fee, which together can double the daily cost compared to the planned period.

For rolled-up interest structures, there is a third factor: by the time the extension begins, the interest that has been compounding during the planned term has increased the outstanding balance, so even at the same rate the monthly interest amount is higher. The tool accounts for this by calculating the extension interest on the balance at the end of the planned term rather than on the original loan amount.

How much buffer should I add to the planned term?

There is no single answer because the appropriate buffer depends on the exit strategy and its complexity. For a chain-break where the sale is already agreed, one to two months may be sufficient. For a refurbishment and sale where works could overrun and the sale process has not yet started, two to three months is more prudent. For a refinance exit that depends on the property reaching a specific condition, the buffer needs to account for both the works timeline and the refinance application timeline.

The tool helps quantify the cost of the buffer. Adding two months to a 9-month term makes it an 11-month facility. The additional retained interest or rolled-up compounding for those two months is the “insurance premium” for avoiding an extension. If the exit lands on time at month 9, the early exit modeller shows the saving from exiting before the full buffered term. In most cases, the buffer cost is a fraction of what a formal extension with fees and rate uplift would cost.

What happens if the lender charges default interest instead of offering a formal extension?

Default interest is a higher rate applied when the facility has expired without redemption and the borrower has not agreed a formal extension. Default rates vary but are typically significantly higher than the contractual rate, sometimes 2% to 4% per month or more, and may compound monthly, meaning the cost accelerates over time. The higher rate is intended to incentivise prompt exit. On a £300,000 facility, default interest at 3% per month is £9,000 per month, which is three times the cost of a typical 1% rate during the planned term.

Default interest clauses are not always enforceable. Under the penalty doctrine established in Cavendish v Makdessi, a default interest clause may be struck down if the rate is extortionate, exorbitant, or unconscionable in relation to the lender’s legitimate interest. Individual borrowers may also have protections under the unfair relationship provisions of the Consumer Credit Act. If default interest is being applied or threatened, professional legal advice should be sought.

Avoiding default interest requires proactive communication with the lender before the term expires. If the exit is delayed, approaching the lender with a revised timeline and evidence of progress (sale listing, refinance application, works completion evidence) is far more likely to result in a negotiated extension at manageable terms than waiting until the term has already expired. The guide on strong exit strategies covers how to structure the exit plan in a way that minimises the risk of default.

Update log: July 2026

What changed in this update

The calculator was updated with accessibility improvements including keyboard navigation for the interest structure selector, screen reader support across all sliders and result panels, and colour contrast adjustments throughout the tool to meet WCAG 2.1 AA standards. The daily cost panel now includes a two-week overrun figure alongside the daily and weekly costs.

Market data references were reviewed against current 2026 sources. Extension fee and rate uplift ranges were tightened to reflect the most commonly cited figures across UK bridging lenders. A link to the main bridging loan calculator was added to the related tools section, and the tool footnote was expanded to clarify how extension interest is treated on serviced interest structures.

The default interest section was updated to clarify that default interest clauses may be challengeable under the penalty doctrine and the Consumer Credit Act, and to note that default interest may compound. Context was added on the distinction between regulated and unregulated facilities and how this affects extension terms and borrower protections. The disclaimer was expanded to reflect these additions.

This tool is for illustrative purposes only and does not constitute financial advice. Extension terms, rates, and fees vary between lenders and are subject to the lender’s discretion and the borrower’s circumstances. Some lenders may decline to offer an extension. Default interest rates apply if the facility expires without redemption or a negotiated extension, and the enforceability of default interest clauses depends on the specific terms and circumstances. Whether a bridging loan is regulated or unregulated depends on the intended use of the security property and affects the borrower’s protections. Your property may be repossessed if you do not keep up repayments on a bridging loan. Professional advice should be sought before entering into or extending a bridging loan facility. Actual outcomes will depend on your individual circumstances.