Most venture-backed founders think about growth funding as a binary choice: raise the next round or slow down. It is an understandable framing because equity is the funding route the venture ecosystem is built around and the one every founder knows. But it leaves out a middle path that a great many scale-ups now use, and that is venture debt: borrowing against the momentum you already have, to fund the next phase without handing over more of the company to do it.
The logic is straightforward. Every round you raise prices, your business is at whatever the market thinks it is on that day. If you can reach a materially better set of metrics before you raise again, you sell less of the company for more money. Venture debt exists to buy you that time and to fund that push. It is not a replacement for venture capital, and it is not free, but for a business with real revenue and a clear path to the next milestone, it is often the cheapest capital on the table.
The timing matters more than usual because the equity market has become harder and more concentrated. The British Business Bank's Small Business Equity Tracker reports that equity investment into UK smaller businesses fell by 4% to £12.3bn in 2025, with investors concentrating capital into fewer, larger transactions. Early-stage activity took the brunt: seed and venture-stage deals were 27% and 13% lower, respectively. For a company between rounds, that is the context worth understanding, because a market where capital is pooling into a smaller number of big deals is a market where raising takes longer and prices less kindly.
This guide explains what venture debt is, how venture lending works alongside equity, the dilution maths that makes it compelling, what lenders look for, and, just as importantly, when a venture loan is the wrong answer.
Venture debt is a loan made to a venture-backed or high-growth company, usually one that has already raised institutional equity, to fund growth or extend runway between rounds. It sits alongside the equity on the cap table rather than replacing it, which is the essential point: the venture capital investors stay where they are, the founders keep their shares, and the business takes on borrowing that is repaid from cash flow over time.
It goes by several names. Venture lending, venture debt capital and a venture loan all describe broadly the same thing, and in practice, the structure varies. It might be a term loan repaid over two to four years, a facility drawn to fund a specific expansion, or, as FBX often arranges venture debt, a cash flow loan sized against the company's earnings and trajectory rather than against hard assets. What unites them is that the lender is underwriting growth and the quality of the business behind it, not simply a balance sheet full of collateral.
The critical difference from equity is what you give up. Equity is permanent capital, sold in exchange for a share of everything the company ever becomes. Debt is temporary capital, rented in exchange for interest and repaid. One dilutes you forever; the other costs you money for a period. That distinction is the whole argument.
It is worth being precise about the trade-off, because the two instruments are not interchangeable and a good adviser will not pretend they are.
| Venture capital | Venture debt | |
| What you give up | A permanent share of the company | Interest, and repayment over time |
| Repayment | None; investors are repaid on an exit | Scheduled, from cash flow |
| Cost if you succeed | Very high; the shares you sold are the ones that appreciate | Fixed; the interest is the interest |
| Cost if you struggle | Low; equity absorbs the downside | Real; repayments continue regardless |
| What it funds well | Long-horizon risk, unproven models, deep R&D | Defined growth pushes, runway to a milestone |
| Speed | Months, and a full process | Often weeks |
Equity is the right instrument for genuine risk, the kind of spending where the outcome is unknowable, and the business needs capital that can absorb a failure. Debt is the right instrument where the outcome is reasonably predictable: you know that hiring a sales team, funding a marketing push, financing customer acquisition or bridging a working capital gap will produce revenue on a timeline you can see. Rent money you can repay; sell equity only for risk you cannot.
Here is the calculation that makes venture debt worth understanding, expressed simply.
When you raise a round, you sell a percentage of the company at the valuation the market gives you today. That valuation is a function of your metrics: revenue, growth rate, retention, margin, whatever your sector rewards. If you raise now, at today's numbers, you sell a given slice of the business. If you can raise in nine or twelve months, having grown into a substantially stronger set of numbers, the same amount of money costs you a smaller slice. The gap between those two slices is the value of the time.
Venture debt buys that time. It is the runway, and often the growth spending itself, that gets the business from the metrics it has to the metrics it wants, so that when the next equity round comes, it is raised from a position of strength. The interest you pay on the loan is the price of that option, and where the business genuinely does grow into a better valuation, it is very often a fraction of the equity it saves.
The argument only means something with figures attached, so here is a simple, illustrative comparison. The numbers below are worked examples chosen for clarity, not a quote or a market rate, and every real deal will differ.
Take a company that needs £2m to fund its next phase of growth, and that is currently valued at £10m before any new money.
Option A: raise the equity now. You raise £2m at a £10m pre-money valuation, so the company is worth £12m afterwards, and the new investors own £2m of £12m, which is 16.7% of the business. That 16.7% is gone permanently.
Option B: borrow the £2m, grow, then raise. You take £2m of venture debt, spend it on the same growth, and twelve months later, the business has grown into a £16m pre-money valuation. Now you raise the same £2m of equity. The company is worth £18m afterwards, and the new investors own £2m of £18m, which is 11.1%.
The difference is 5.6 percentage points of the company. On an £18m business, that is roughly £1m of value that stayed with the existing shareholders. Against that, the debt costs you interest for the year, and at an illustrative 12% on £2m, that is around £240,000, plus fees. Simplifying, you spent something in the region of a quarter of a million pounds to keep about a million pounds' worth of equity.
| Raise equity now | Borrow now, raise in 12 months | |
| Pre-money valuation | £10m | £16m |
| Amount raised | £2m | £2m |
| New investors own | 16.7% | 11.1% |
| Cost of the debt | None | Around £240k in interest, plus fees |
| Dilution avoided | About 5.6 percentage points, roughly £1m of value |
And the honest counter-case. Run the same numbers where the growth does not occur. If twelve months later the business is still valued at £10m, you raise the £2m anyway and still give away 16.7%, except now you have also paid the interest, and you have a loan to repay. Debt bought you time but not value, and it made the position worse rather than better.
That asymmetry is the whole discipline. The question is never "can we borrow?" It is "Will this money change what we are worth?" Where the answer is a confident yes, the maths is compelling. Where it is a hopeful maybe, it is not.
An example from our own work shows how this plays out. A healthcare company supplying the NHS was growing faster than its own budget and projections, winning new contracts it needed funding to service, and wanted to reach its Series B without diluting further. FBX arranged a £3.25m venture debt facility on an interest-only basis, which gave the business the liquidity to take on the new contracts while protecting cash flow, and positioned it to approach the Series B from a stronger footing rather than raising into its growth. That is the thesis in one deal: the facility cost money, and it cost less than the equity it preserved.
Venture lending tends to work best in a recognisable set of situations.
It is only fair to say that when debt is not the tool, because a lender or an adviser who never says no is not worth listening to.
If the business is pre-revenue, or revenue is too early and unpredictable to service repayments, debt adds a fixed obligation to an already uncertain picture, and equity is the more honest instrument. If the spending is genuinely speculative, long-horizon R&D with an unknowable payoff, that is precisely the risk equity exists to carry. If the runway is already short and there is no clear milestone within reach, a venture loan can compound the problem rather than solve it, because the repayments start whether or not the plan works. And if what the business really needs is permanent capital to absorb ongoing losses, a loan is the wrong shape entirely.
Debt has one unforgiving quality that equity does not: it must be repaid on schedule, regardless of how the quarter went. That is exactly why it is cheaper, and exactly why it deserves respect.
Venture lenders do not underwrite the way a traditional bank does, because a fast-growing, asset-light company rarely has the collateral or the profit history a bank wants to see. What they assess instead is the quality of the growth and the credibility of the plan.
In practice, that means they look closely at revenue quality: how recurring it is, how well customers retain, how concentrated the customer base is, and how predictable the forward book looks. They look at the trajectory and the unit economics, because a business that spends efficiently to acquire customers who stay is a very different credit from one buying growth at any cost. They look at the equity behind you, the investors on the cap table, how much they have put in, and whether they are likely to support the business again, since a strong, engaged investor base is itself a form of comfort to a lender. They look at cash burn and runway, and how the loan changes both. And they look at the plan, specifically whether the money funds something that generates the cash to repay it.
The practical implication is that a venture debt conversation is won or lost on preparation. A clear, well-evidenced case, with realistic forecasts, honest metrics and a coherent story about what the money does, gets better terms than an equally good business presented poorly. This is the part where a specialist earns their place by knowing which lenders are active, what each will actually fund, and how to present the business in the way a credit team needs to see it.
Venture lending is priced for the risk it takes, so it costs more than a secured bank facility and considerably less than equity. Pricing has also moved with the wider rate environment, since the Bank of England's base rate sets the floor beneath most commercial borrowing, which is worth factoring into any comparison against a round.
Beyond the headline rate, the terms that matter are the ones that shape how the facility behaves. The repayment profile determines how quickly the loan starts drawing on cash, and an interest-only period at the start can matter a great deal to a business investing for growth. Covenants set the conditions you must keep meeting, and for a scaling company, those need to reflect how the business actually operates rather than how a lender wishes it did. Some facilities carry warrants, giving the lender a small equity participation, which reintroduces a little dilution and should be weighed rather than waved through. And security, fees and any prepayment charges all belong in the true cost, not just the rate.
The point is that a venture loan is a package, not a number. The cheapest headline rate attached to a rigid structure and tight covenants can be far worse for a growing business than a slightly costlier facility that flexes as it scales.
At FBX Capital Partners, this is a large part of what we do for venture-backed businesses. We are an independent UK debt advisory firm, working across the whole lending market rather than a single lender's product set, and we arrange venture debt, cash flow loans and growth capital for companies that want to fund their next phase without giving away more of the business than they need to.
If you are weighing a round against a facility, the useful first step is simply to model both: what the equity would cost you at today's valuation, against what the debt would cost you to get to a better one. Often, the answer is obvious once it is on paper, and sometimes the honest answer is that a round is the right call. Either way, it is a conversation worth having before the runway gets short, because options narrow quickly when time does.
It is a loan to a venture-backed or high-growth company, usually one that has already raised equity, used to extend runway or fund growth. It sits alongside the venture capital on the cap table rather than replacing it, and it is repaid from cash flow rather than by selling shares.
Not always, but it helps. Venture lenders take comfort from institutional investors on the cap table and from the diligence those investors have already done. That said, the underlying test is the quality of the revenue and the credibility of the plan, so a strong, growing business without a classic VC round may still be fundable, sometimes through a cash flow loan or an asset-based structure instead.
