Mezzanine finance is the layer of capital that sits between the money your bank will lend and the equity you would have to sell. It behaves partly like debt and partly like equity: it is typically unsecured, it ranks behind senior debt if things go wrong, and it ranks ahead of common equity — which is to say ahead of you. Founders usually meet it at a specific moment: a bank has lent as much as it will against the assets and cash flows on offer, the deal or the growth plan needs more, and selling shares to close the gap feels like paying for a twelve-month problem with a permanent answer. Mezzanine is the instrument built for that gap. It is also priced for the risk it carries, and it comes with conditions that change how the business has to be run. Understanding what it costs — in money, in control and in reporting — before you approach anyone is the difference between using it well and being surprised by it.
This is a structural explainer for founder-led businesses, not tax or investment advice. Terms vary by lender and by deal; the description below follows British Business Bank and Development Bank of Wales guidance.
Where mezzanine sits in the capital stack
Think of the money in a business as a queue for repayment if the worst happens. Mezzanine's whole identity is its position in that queue.
| Layer | Ranking on repayment | Typically secured? | Cost to you |
|---|---|---|---|
| Senior debt (bank) | First | Usually, against assets | Lowest |
| Mezzanine | After senior debt | Usually unsecured | Higher — a risk premium |
| Equity (your shares) | Last | — | Permanent dilution |
Because it is subordinated and usually unsecured, the mezzanine lender has less protection than the bank and takes more risk — so it charges more. British Business Bank describes the risk premium as potentially reaching up to 20%. That figure is theirs, and it is a characterisation of the premium rather than a quote you should expect; the point to take is the order of magnitude relative to senior debt, not the number itself.
What you are buying with that premium is not having to sell equity today. Whether that is a good trade depends entirely on what the business is worth later, which is a judgement, not a calculation.
What makes it different from a normal loan
Three features do most of the work, and the second is the one founders under-appreciate.
It is usually unsecured. There is no asset to take, which is precisely why it is available when the bank has stopped. It also means the lender is underwriting your cash flows and your plan, not your balance sheet — so the diligence is about the business, not the assets.
The interest can roll up. Interest may be paid in cash, rolled into the loan balance, or split between the two, depending on what the business can afford. If a scheduled payment would break the cash flow, some or all of it can be deferred to later. That is genuinely useful during a build-out phase — and it is also compounding. Rolled-up interest is not free; it is a larger repayment later, and it grows while you are not looking.
It may convert to equity. Agreements can carry equity conversion rights, so if repayment is not possible the lender may take a share of ownership — but only after other lenders and investors have been repaid. This is the clause to read twice. It is the mechanism by which a financing decision becomes an ownership decision.
When does mezzanine actually fit?
In our experience it fits a narrow set of situations well and a wide set badly.
It tends to fit when:
- The gap is finite and identifiable. You can name what the money does and when the business stops needing it. Mezzanine is bridging capital in spirit, even when the term is long.
- Cash flow is real but lumpy. The roll-up feature exists for businesses whose cash is coming, just not evenly.
- You are buying something. Acquisition structures are where mezzanine is most at home — it fills the space between what a bank will lend against the target and what the vendor wants. If you are weighing a sequence of acquisitions, this is the layer that usually makes the second and third ones possible; we set out the strategic question in buy-and-build for a scaling business.
- A management team is buying the business. The same logic drives buyout structures, which we cover in management buyouts in a founder-led business.
It tends not to fit when:
- the shortfall is structural rather than temporary — mezzanine on a business that is losing money buys time and adds cost;
- the plan depends on the roll-up feature from day one, which means the business cannot service the debt at all;
- you would not survive the conversion clause being exercised.
What it demands of the business
This is the part that gets skipped, and it is the part that changes daily life.
A mezzanine lender pricing unsecured, subordinated risk will want to see the business the way an investor does: regular management information, covenant compliance, and visibility of the plan against actuals. Reporting that was adequate for a bank secured on property is usually not adequate here.
For most founder-led businesses that is a genuine operational step up — and it arrives at the same time as the money, not after it. If your management accounts currently take three weeks and get argued about, that is a problem to solve before drawdown, not after. It is the same discipline that growth-stage investors expect, and we describe what they look for in what an investor actually looks at in a founder-led business.
Mezzanine or equity — the question underneath
The instinct is to compare the cost of mezzanine with the cost of equity and pick the cheaper. That comparison is usually wrong, because it treats a fixed cost and a permanent share of the upside as the same kind of thing.
Four tests we would apply before choosing:
- How confident are you in the plan the money funds? Mezzanine's cost is fixed whether the plan works or not. Equity's cost rises only if it does. Confidence favours debt; uncertainty favours sharing the risk.
- What is the business worth to you in five years? If you believe the value is going to be materially higher, selling equity now is expensive in a way no interest rate captures.
- Can you service it in a bad year, not an average one? Model the downside. The roll-up feature helps, but it is a deferral, not a rescue.
- What happens if the conversion clause bites? If the answer is "we lose control of the business", the structure is wrong regardless of the price.
The founders who use mezzanine well treat it as a deliberate, temporary layer with a defined job and a defined exit. The ones who struggle reached for it because it was the only capital still available — which is a signal about the plan, not about the instrument. Where a business is in its lifecycle changes which answer is right, and we map that in the stages of scaling a business.
