Topco, Midco & Bidco Explained: How a Buyout Is Structured

Key takeaways

A fund does not buy a business directly. It incorporates a chain of new shell companies — Topco at the top, one or more Midcos in the middle, Bidco at the bottom — and Bidco is the entity that actually acquires the target. The stack is not bureaucracy; it is the architecture that decides where each pound of debt and equity sits and what it ranks behind
The order is dictated by structural subordination. A lender's priority is set by how close to the operating assets it sits. Senior secured debt is borrowed at Bidco, next to the target's cash flow; junior debt, mezzanine and PIK notes sit higher, at Midco; the equity sits highest of all, at Topco. A creditor lending higher up the stack ranks behind the creditors of every company below it — before any intercreditor agreement is even signed
The fund's equity goes in mostly as the institutional strip — roughly 90% shareholder loan notes or preference shares carrying a fixed preferred return, and only ~10% ordinary shares. Management invests only in ordinary shares, the sweet equity. Because the loan notes are repaid first and the ordinary shares capture the geared upside, management can fund around 1% of the total equity and own close to 10% of the shares that actually appreciate
The gap is measured by the envy ratio — the multiple of what the institution effectively pays per ordinary share versus what management pays — and it runs at roughly the strip ratio, around 10x. The structure also does the tax work (interest deductibility, subject to the corporate interest restriction), houses bolt-ons under Bidco, and delivers a clean exit: the buyer simply purchases Topco, the company sitting above the entire stack

A Fund Does Not Buy the Company — a Chain of New Companies Does

When a sponsor wins an auction, the buyer named in the sale agreement is almost never the fund. It is a company incorporated days earlier with no history, no assets and a name like "Project Falcon Bidco Limited". Above it sit two or three more shells, freshly minted for the deal, stacked one on top of the next. The fund subscribes for shares at the top; the bottom company writes the cheque for the target.

This stack — Topco, Midco, Bidco, and sometimes a Holdco above them all — is the standard architecture of a European leveraged buyout. It looks like over-engineering, and a student seeing it for the first time assumes it is a tax dodge or a lawyer's invoice generator. It is neither. The stack exists because a buyout has to do three incompatible things at once: borrow senior debt against the operating company, layer junior debt and shareholder funding above it without contaminating that senior claim, and split the equity between a fund and a management team on deliberately unequal terms.

One company cannot hold all of that cleanly. A chain can, and where each instrument attaches in the chain is the whole point — so start with the principle that fixes the order.

Structural Subordination: The Floor You Lend At Decides Your Priority

The reason the stack has an order is a single idea that sits underneath all of leveraged finance: structural subordination. A company's creditors have first claim on that company's assets. Anyone holding shares in it — including a parent company higher up the chain — has only a residual claim, paid out after the company's own debts are met. So a lender to a parent ranks behind the creditors of its subsidiaries, because the parent's only real asset is shares in the subsidiary, and shares pay last.

Apply that to the stack and the design becomes obvious. Senior lenders want to be as close to the target's cash flow and assets as possible, so the senior secured term loans and revolver are borrowed at Bidco, the company that owns the target directly and can grant security over its shares and assets. Junior debt — second lien, mezzanine, PIK notes — is pushed up to Midco, whose only asset is its shares in Bidco. That placement alone makes it junior: Midco's lenders cannot touch the operating assets until Bidco's senior lenders are satisfied.

Structural vs contractual subordination — interviewers test the difference Junior debt is subordinated in two distinct ways, and candidates routinely conflate them. Contractual subordination is a promise: an intercreditor agreement in which the junior lender agrees, on paper, to be paid after the senior lender. Structural subordination needs no agreement at all — it is a fact of where the debt sits in the corporate chain. Debt at Midco is structurally subordinated to debt at Bidco because Midco is one company further from the assets, and its claim on those assets is nothing but equity in the company that owns them. The strongest junior position combines both; the weakest relies on structure alone. A candidate who can separate "subordinated by contract" from "subordinated by structure" is showing they understand why the stack is shaped the way it is, not just that it has layers.

Equity sits highest of all, at Topco, because equity is the residual claim by definition — last in every queue. And it is at Topco that the most interesting part of the structure lives, because the equity is not one instrument but two, split between two parties on very different terms.

Three Companies, Three Jobs: Where the Debt and the Equity Attach

Each company in the chain has a defined role, and the role is defined by what attaches to it. The table below is the structure a London PE associate sees on almost every deal; the entity names vary, the logic does not.

Entity	What sits here	Who holds it	Rank on the assets
Topco	The equity: institutional strip (loan notes / prefs + ordinary) and management sweet equity	The fund and the management team	Residual — last in line
Midco	Junior debt: second lien, mezzanine, PIK / shareholder loan notes	Credit funds, mezz lenders, the fund	Structurally junior to Bidco's debt
Bidco	Senior secured debt: term loans and revolver; acquires the target	Banks, CLOs, direct lenders	First — secured on the target's assets
Target	The operating business and its cash flow	Owned 100% by Bidco	Generates everything the stack is repaid from

Read top to bottom, the chain is a ranking: the assets and cash flow live at the target, the senior debt sits one company above them, the junior debt one above that, and the equity at the summit. Cash flows up the chain to service each layer in turn — interest at Bidco first, then Midco, then whatever is left accrues to the equity at Topco. The debt stack and the company stack are the same queue viewed from two angles.

Often there are two Midcos rather than one — a Midco for third-party junior debt and another for the fund's own shareholder loans — to keep the lenders' security and the shareholders' funding on separate rungs. The principle is unchanged: more rungs, finer control over who ranks where. With the debt placed, the question becomes how the equity at the top is divided.

The Institutional Strip: The Fund Invests 90% as Loan Notes, 10% as Shares

The fund does not put its equity cheque in as ordinary shares. It invests through a strip — a fixed ratio of shareholder loan notes or preference shares to ordinary shares, typically around 90:10. The loan notes carry a fixed preferred return, often paid in kind so it compounds rather than draining cash, and they rank ahead of the ordinary shares: on any exit, the loan notes are repaid with their accrued return before a penny reaches the ordinary equity.

The ordinary shares are the geared instrument. Once the debt and the loan notes are repaid, everything left flows to them, so they carry the leverage of the whole structure on a thin base. The fund holds most of them, but not all — and the slice it leaves for management is the entire reason the strip is built this way.

Common mistake Describing the loan notes as "debt the fund lends to the deal" and stopping there. They are equity in economic substance — the fund's own money, ranking behind the third-party lenders, at risk if the deal fails. What the loan-note wrapper buys is a fixed, senior-ranking return that sits ahead of the ordinary shares, plus historically a measure of tax efficiency. Calling them "shareholder debt" is fine; treating them as if they were as safe as the bank's senior loan is wrong. They are the fund's equity, dressed to rank first among the equity — and to leave the upside concentrated in the ordinary shares where the incentive needs to be.

That concentration is the mechanism behind sweet equity, and it is worth putting real numbers through to see how far a small management cheque stretches.

Worked Example: How Management's £3m Owns 9% of the Upside

Take a buyout needing £300m of equity into Topco. The management team invests £3m — 1% of the total. The fund provides the other £297m through the strip: 90% as loan notes and 10% as ordinary shares.

1. The fund's strip: £267m loan notes, £30m ordinary. Of its £297m, 90% (£267m) goes into loan notes carrying a preferred return, and 10% (£30m) into ordinary shares at the same price per share management will pay.

2. Management's £3m is all ordinary shares. Management funds no loan notes. Its entire £3m buys ordinary shares — the only instrument that captures the upside above the loan-note return.

3. The ordinary share register: ~91% fund, ~9% management. Total ordinary equity is £33m (£30m + £3m). The fund holds £30m / £33m ≈ 91%; management holds £3m / £33m ≈ 9%. Management funded 1% of all the capital but owns ~9% of the shares that appreciate.

4. The loan notes get repaid first. On exit, the £267m of loan notes plus their accrued return come off the top. Whatever value remains is split 91/9 — so management's 9% is geared to the equity gain, not diluted by the bulk of the fund's money that sits safely in the loan notes ahead of it.

The result is that management's cash is roughly nine times more concentrated in the upside than its share of the funding would suggest — and there is a single number that captures exactly how favourable that split is.

~10x The envy ratio in the worked deal — the multiple of what the fund effectively pays per ordinary share (£297m for ~91%) versus what management pays (£3m for ~9%). It runs at roughly the strip ratio, because the fund's loan notes ride alongside its ordinary shares while management's cheque does not. A high envy ratio is the institution deliberately overpaying for its ordinary shares so management can buy in cheaply and stay hungry

Insider tip The envy ratio is negotiated, not given. A management team with leverage — a proven CEO the fund needs — pushes for a higher envy ratio, meaning cheaper sweet equity and more upside for the same cheque. A fund worried about alignment pushes the other way and may require management to invest more, sometimes by rolling proceeds from the previous deal. Knowing that the envy ratio is the dial on the management-incentive negotiation, not a fixed market convention, is what separates a candidate who has read about sweet equity from one who understands it is the output of a bargain over who is hungrier for the upside.

The strip and the envy ratio explain why the equity sits at Topco and why it is split the way it is. But none of it answers the first question a sceptic asks: why build a chain at all?

Why Not One Company? Tax, Bolt-Ons, and a Clean Exit

Beyond structural subordination, the stack earns its complexity three more ways. The first is tax. Interest on third-party debt and, historically, on shareholder loan notes is deductible against the group's profits, sheltering taxable income — though in the UK the corporate interest restriction now caps net deductions at roughly 30% of tax-EBITDA above a £2m de minimis, which has pushed more shareholder funding toward preference shares and offshore-held instruments. The placement of debt at the right entity is what lets the deductions land where the profits are.

The second is bolt-ons. A buy-and-build platform acquires add-ons through or beneath Bidco, slotting each new business into the existing structure without disturbing the equity above. The third is the exit: when the fund sells, the buyer simply purchases the shares of Topco, acquiring the entire group — equity, debt and target — in one clean share sale, with the loan notes repaid and the senior debt refinanced as part of completion. The same chain also makes a dividend recapitalisation straightforward: new debt is raised low in the stack and the cash is pushed up to repay loan notes and return capital to the fund early.

Common mistake Assuming the holding-company stack is purely a tax structure. Tax shapes the details — which jurisdiction Topco sits in, whether the strip uses loan notes or prefs, where the interest is deducted — but it is not the reason the chain exists. Strip out every tax consideration and a sponsor would still need the stack, because structural subordination and the equity split require it: senior lenders demand to sit next to the assets, junior lenders must rank above them without a contract doing all the work, and the strip needs a single Topco where both classes of equity meet. Treat tax as the explanation and you will miss the structural logic an interviewer is actually probing.

Put together, the stack is less a tax wrapper than a control system — for priority, for incentives, and for what happens on the way in and the way out. That is exactly why it shows up in interviews.

How This Is Tested: "Why Is a Buyout Structured Through Topco, Midco and Bidco?"

The question is a London PE and leveraged-finance staple, and the weak answer is "for tax". The strong answer leads with structural subordination: senior debt sits at Bidco to be closest to the assets, junior debt at Midco so it ranks behind by structure as well as contract, and the equity at Topco because it is residual. Naming where each instrument attaches, and why position equals priority, is the fastest way to show you understand the architecture rather than the diagram.

The follow-ups go to the equity. What is the institutional strip? Mostly loan notes or prefs with a fixed return, a thin slice of ordinary shares. Why does management invest only in ordinary shares? So its cheque is geared into the upside that sits above the loan notes — that is sweet equity. What is the envy ratio, and who does a high one favour? The multiple the fund overpays per ordinary share, and a high one favours management. A candidate who can move from the debt's position, to structural versus contractual subordination, to the strip, to the envy ratio is describing a buyout's plumbing the way the people who build it do.

The Verdict: The Stack Is a Map of Who Ranks Where

The Topco–Midco–Bidco chain looks like complexity for its own sake and is, underneath, a single coherent answer to a single problem: a buyout has to rank many claims against one stream of cash flow, and a company's position in the chain is what fixes its rank. Senior debt sits low to be near the assets, junior debt sits above it to rank behind, and the equity sits at the top because it is paid last — structural subordination doing the work before any lawyer drafts an intercreditor clause.

The equity at the top is then split to align the people who run the business. The fund takes a safe, senior-ranking return through the strip and leaves the geared ordinary shares concentrated in management's hands, paying ten times as much per share to do it. Tax, bolt-ons and a clean exit are real benefits, but they are consequences of a structure built first for priority and incentive. Read the stack as a map of who ranks where, and every entity in it has an obvious reason to exist.

Anyone can recognise that a buyout runs through shell companies with odd names — that is the diagram. The judgement is knowing why: that the floor a lender sits at decides its priority, that Bidco holds the senior debt because it is next to the assets, that the fund's strip is 90% loan notes so the ordinary shares stay geared, and that an envy ratio near 10x is the institution deliberately overpaying for its shares so management buys in cheap. Reading the stack as a ranking system rather than a tax trick is the difference between someone who has worked inside a buyout structure and someone who has seen a picture of one.

Careers: An Associate Maps Every Pound to an Entity

On a live deal the structure is not a diagram the associate admires — it is a model they build entity by entity. The sources-and-uses has to balance at the right company: senior debt drawn at Bidco, junior debt and shareholder loans at Midco, the strip and sweet equity subscribed at Topco, each with its own line, its own return, and its own place in the waterfall. Get the placement wrong and the returns bridge that flows up to the fund is wrong with it.

The judgement shows in the equity split. What strip ratio, and therefore what envy ratio, does this management team command? How much should they be required to invest to be properly aligned? Where do the loan notes' accrued returns sit relative to a third-party refinancing? An associate who treats the stack as a legal formality produces a model that ties but misstates who gets paid; one who understands it as a ranking system produces a structure the deal team can take to lenders and a management team at once. The first keeps the file moving — the second is the work the seat exists for.

Take Your Preparation Further

The holding-company stack sits at the centre of how a buyout is assembled, so read it alongside the pieces it connects. Start with the LBO debt stack, which is the same queue seen from the lenders' side, and management equity and sweet equity, which is what the strip at Topco is built to create. For how the return is made and shared once the structure is in place, the value-creation bridge and the carried-interest waterfall; for the model underneath it all, the LBO model and the paper LBO; and for a deal where the same structure meets public-market rules, the UK take-private.

For the valuation methods that set the entry multiple the structure is built on, download our free Valuation Methods Cheat Sheet, and to build the buyout yourself — debt by tranche, the equity strip, and a returns bridge — see the LBO Model Template.

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Topco, Midco, Bidco: Why a Buyout Is Built as a Stack of Holding Companies — Structural Subordination, the Institutional Strip, and Where Sweet Equity Sits