Interbay Development Finance Review (2026)

Interbay Development Finance at a Glance

Key Facts

Key Facts

Key point	Details
Provider type	Specialist development finance lender, part of OSB Group plc
Developer-exit LTV	Up to 75%
General bridging LTV	55% on newer products
Indicative rate	From 0.79% per month (no representative APR published)
Loan size	No published minimum or maximum; case studies from £600,000 to £54.5 million
Access	Broker-only; no direct applications accepted
Underwriting	Case-by-case via a named Transactional Credit Committee
Parent group	OSB Group plc (also Kent Reliance, Prestige Finance, Charter Savings Bank)
Verified 30 April 2026.

What Is Interbay Development Finance?

Interbay is a specialist development finance lender operating inside OSB Group plc, the same group that also trades as Kent Reliance, Prestige Finance and Charter Savings Bank.

That ownership matters in practice: OSB Group reported £1.2 billion of originations across its lending businesses in Q1 2026 alone, up 11% on the year before. That balance-sheet depth is what lets Interbay take on the larger, more complex transactions its case studies describe.

Unlike a mainstream bridging lender with a standard product menu, Interbay underwrites every deal individually through its Transactional Credit Committee. That gives it room to fund situations a rules-based lender would decline.

It also means there’s no published rate card for you to check against before you commit time to an application. That’s the trade-off: more flexibility, less certainty.

How Interbay Development Finance Works

A broker packages the deal (the scheme, the developer’s track record, the exit strategy) and submits it to Interbay’s Transactional Credit Committee. The committee assesses the transaction on its own merits rather than against a fixed criteria checklist, and returns terms specific to that deal.

That case-by-case model is why two similar-looking projects can land very different terms from Interbay: the committee is pricing the specific risk in front of it, not applying a published grid.

Ground-Up Development vs Heavy Refurbishment

Interbay’s published case studies lean toward refinance and developer-exit transactions on completed or near-complete schemes rather than ground-up funding from foundation stage.

The £54.5 million central London office refinance and the £24.9 million refinance-and-development loan both describe later-stage, complex situations rather than day-one ground-up builds.

If your project is still at the ground-up or early heavy-refurb stage, confirm with your broker whether Interbay is genuinely active in that segment before you invest time preparing a submission. The lender’s public evidence base skews toward exit and refinance.

Main Loan Options

The two headline products are developer-exit loans, at up to 75% LTV, and general bridging on newer products, capped at 55% LTV. Both sit within Interbay’s wider bridging-finance range rather than as separate standalone product lines.

Loan size is not capped by a published figure at either end. The case studies span from a £600,000 commercial conversion to a £54.5 million refinance, which suggests Interbay will consider a wide range of deal sizes rather than specialising in one band.

Interbay Development Finance Rates and Fees

Interest Rates and Arrangement Fees

The only published rate figure is a headline “from 0.79% a month”: a floor, not a quote. On the monthly floor alone, that translates to a headline annualised cost of roughly 9.5% before fees, though your actual rate will reflect deal size, LTV, borrower profile and asset type.

There is no published arrangement fee schedule either. What gets cited across the specialist bridging market generally is 1-2% plus third-party costs (RICS valuation, legal fees for both sides).

That’s a market assumption, not a confirmed Interbay figure. Don’t budget against a number you can’t confirm, and don’t take the 0.79% floor as gospel. Get the real figure from your broker first.

Additional Fees and Charges

Beyond the assumed arrangement fee, expect the usual specialist development-finance costs: a monitoring surveyor’s fees (paid by the borrower even though the surveyor works for the lender), RICS valuation costs, and legal fees on both sides of the transaction.

None of these are published by Interbay specifically, so confirm the full fee schedule with your broker before you sign anything.

What Affects Your Rate

Because every deal is priced individually by the Transactional Credit Committee, Interbay does not publish the factors that move your rate above the 0.79% floor.

Based on how specialist development lenders generally price risk, expect deal size, LTV, the developer’s track record, the asset type, and exit strategy certainty to all feed into the final number.

A larger, well-evidenced transaction with a credible exit (like the £54.5 million refinance case study) is likely to price differently from a smaller, higher-risk scheme.

But we couldn’t find a published rate grid to confirm it. Treat this as a general market pattern, not an Interbay-specific promise.

Interbay Development Finance Eligibility

Who Can Apply

You cannot apply to Interbay directly. Every application must come through a broker, who packages the deal and submits it to the Transactional Credit Committee on your behalf. If you do not already have a broker, that is the first thing to sort out before you go any further.

Beyond the broker-only rule, Interbay does not publish a fixed eligibility checklist. Decisions are made case by case, which means there is no simple yes/no test you can run yourself before engaging a broker.

Experience, GDV and Loan-to-Cost Requirements

We looked for a published experience, GDV (Gross Development Value) or loan-to-cost threshold and found none. Interbay weighs these factors deal by deal, where a lender like Aldermore states an up-to-65%-LTGDV criterion upfront.

In practice, that means a first-time developer with a strong professional team may still get a hearing, but has no published benchmark to check themselves against beforehand, unlike a competitor with explicit track-record requirements published in advance.

Site, Planning and Professional Team Requirements

No Interbay-specific planning-status or professional-team criteria are published.

Based on standard specialist development-finance practice, expect the committee to want clarity on planning status (full permission carries the least risk) and a qualified professional team (architect, quantity surveyor, main contractor) in place before drawdowns begin.

Confirm Interbay’s actual requirements through your broker rather than assuming the market-standard position applies without exception.

Interbay Development Finance Application Process

How to Apply

There is no self-serve or direct application route. Your broker packages the scheme details, your track record, the exit strategy and supporting documents into a submission for the Transactional Credit Committee.

If you submit a complete package first time, rather than a partial one your broker has to chase you to finish, you avoid adding your own delay on top of the committee’s.

Once it goes in, you’re working in the dark: left waiting on the committee for terms, with no published clock to measure that wait against.

Because the process is broker-led and case-by-case, timelines are not published. The £54.5 million central London refinance case study completed in 14 weeks, which gives a rough sense of scale for a complex transaction, but a smaller or simpler deal could move faster.

Documents, Appraisals and Checks Needed

No published document checklist exists for Interbay specifically.

Based on standard practice for this loan size and complexity, expect to need a detailed scheme appraisal, a professional team schedule, planning documentation, and evidence of your track record as a developer.

If you leave gathering that paperwork until your broker asks for it, you’ll be the one holding up your own submission. Confirm the exact list with your broker before you start.

Credit Decision and First Drawdown

The Transactional Credit Committee makes the credit decision after reviewing your broker’s full submission. No published timeline exists for how long this typically takes, and it will vary with deal complexity. While the committee reviews, you end up chasing your broker for progress.

The 14-week completion on the £54.5 million refinance case study is the only public reference point, and that was a large, complex transaction.

Drawdowns, Monitoring and Repayment

Interbay does not publish its own drawdown mechanics, so what follows describes standard specialist development-finance practice rather than an Interbay-confirmed process. Confirm the specifics of your own facility with your broker rather than relying on this as an Interbay-specific guarantee.

How Staged Drawdowns Work

In development finance generally, funds are released in stages against verified build milestones rather than as a single lump sum. A monitoring surveyor certifies each stage is complete before the next tranche is released. In practice, you’re waiting on that sign-off before each tranche lands.

Whether Interbay follows this exact model, and how many tranches it uses, is not published. Ask your broker for Interbay’s specific drawdown schedule before you rely on any assumption.

Monitoring Surveyor and Build Milestones

Across the market, the monitoring surveyor acts as the lender’s eyes on site, verifying progress and certifying drawdowns. The borrower typically pays the surveyor’s fees even though the surveyor works in the lender’s interest.

No Interbay-specific monitoring requirements are published, so confirm this directly through your broker.

Loan Term, Interest and Repayment at Exit

The one confirmed data point here is the £54.5 million central London refinance, structured as a 10-year interest-only loan with the rate fixed for the first five years at 6.99% and flagged with ESG credentials.

That is a specific deal structure, not necessarily representative of Interbay’s standard terms, but it does show the lender is comfortable with long-dated, interest-only structures for the right transaction.

Development finance more broadly tends to roll up interest (added to the balance rather than paid monthly) because the project generates no income until completion, with the full balance repaid at exit. Whether that applies to a given Interbay facility depends on the specific deal terms agreed.

Cost Overruns, Delays and Risk

What Happens If Costs Overrun

No Interbay-specific cost-overrun policy is published.

Ask directly, through your broker, whether Interbay offers a contingency facility within the loan or allows cost-overrun drawdowns. This is one of the most important questions to resolve before signing, and it is not answered anywhere in Interbay’s public material.

Extensions, Delays and Default Risk

Development projects routinely overrun on budget and programme across the market, and what triggers a default varies by lender. If your build slips and you’re waiting on the lender to approve more funds, that delay is yours to carry.

Interbay does not publish its position on programme slippage or the conditions that would trigger a default. Confirm this explicitly with your broker rather than assuming standard market terms apply.

Interbay Development Finance Customer Reviews

Interbay holds a Trustpilot rating of 3.5. That number reads differently here than it would for a consumer lender: Interbay deals with brokers, not borrowers, directly, so genuine borrower-side reviews are structurally limited and the review base is thinner than a retail lender’s.

Verify the current score and review count on Trustpilot before publish, since ratings move over time.

What Customers Like

For a broker-led specialist lender at this scale, the pattern we would expect intermediaries to report is positive commentary on deal complexity appetite and the committee’s willingness to engage with unusual structures.

Set against that: frustration where the lack of a published rate card slows deal comparison.

Confirm current intermediary sentiment before relying on this pattern.

Common Complaints

The predictable friction point with any “from” rate and no published criteria is the expectation gap: a broker or borrower anchors on the 0.79% floor or the 75% LTV headline, then finds the actual terms on their specific deal land somewhere less favourable once the committee has reviewed it.

We’d flag that as the structural risk of opaque, case-by-case pricing generally, not a complaint pattern confirmed against Interbay, but it’s worth setting expectations before a submission goes in.

Interbay Support and Regulation

Customer Support

Because Interbay works through brokers rather than borrowers directly, your primary point of contact for support during the life of the loan is typically your broker, not Interbay itself. Confirm what direct support channels, if any, Interbay makes available to borrowers once a deal has completed.

Regulatory Status and Complaints

Development finance to limited companies and professional developers is largely unregulated by the FCA, which is standard across the specialist lending market rather than an Interbay-specific gap.

Confirm OSB Group’s current FCA authorisation and firm reference number on the FCA Register at register.fca.org.uk before proceeding.

Where any part of a transaction does fall under regulated activity, standard FCA complaint-handling and Financial Ombudsman Service escalation rules would apply.

Where it does not, you would raise concerns through Interbay’s own complaints process instead. Confirm which applies to your specific facility.

Interbay vs Alternatives

Interbay vs Aldermore Development Finance

Aldermore is the clearest direct comparator, because it publishes what Interbay does not: explicit lending criteria of up to £50 million, up to 65% LTGDV, and named track-record requirements.

If you want to know roughly where you stand before spending broker time on a submission, Aldermore gives you that upfront and Interbay does not.

Interbay’s counter-argument is LTV headroom and scale. Its 75% developer-exit LTV beats Aldermore’s 65% LTGDV ceiling, and its case studies (up to £54.5 million) show a willingness to back larger, more complex transactions than a criteria-led lender might take on.

We’d put Aldermore first if transparency matters more to you than the last few points of LTV. If you’re chasing maximum LTV on a developer-exit or handling a genuinely complex transaction, we’d add Interbay to the shortlist through a broker.

Interbay vs Octopus Real Estate Development Finance

Octopus Real Estate is another established name in this space worth checking alongside Interbay, particularly if your scheme sits at a scale or complexity where a specialist real estate lender’s dedicated underwriting team may be a better fit than a generalist bridging lender.

Compare current published criteria and rates for both before committing time to a submission with either.

Interbay vs Other Bridging and Development Lenders

Beyond the two named comparators above, the wider specialist bridging and development finance market includes lenders with varying appetite for LTV, deal size and transparency.

A broker who works across multiple lenders is the fastest way to see how Interbay’s terms compare on your specific deal. We’d treat that cross-market view as essential, because so much of Interbay’s pricing only surfaces after a submission.

Until then, you’re stuck waiting on the process before you know where you stand.

Final Verdict: Is Interbay Development Finance Worth It?

We think Interbay is worth a broker introduction if you are an experienced developer chasing the highest available LTV on a developer-exit loan, or if your transaction is large or complex enough that you need a lender with genuine balance-sheet depth behind it.

The 75% developer-exit LTV beats the 65-70% ceiling most bridging lenders hold to, and OSB Group’s scale is real, not marketing: £1.2 billion in group originations in a single quarter is a meaningful signal of capacity.

The opacity is the real cost, though. No rate card, no LTV-to-rate matrix, and no direct-applicant route mean you cannot compare Interbay against alternatives until a broker has already done the work of submitting your deal.

If you value knowing roughly where you stand before you commit that time, Aldermore‘s published criteria make it the easier starting point.

We’d get quotes from at least two lenders through your broker before committing, and treat every figure we’ve flagged as unconfirmed (drawdown mechanics, cost-overrun policy, arrangement fees) as a question to put to Interbay directly, not an assumption to rely on.

Frequently Asked Questions