Senior debt vs subordinated debt: how the capital stack works

This guide is for business owners, management teams and property developers putting together a funding structure with more than one layer of debt, and for anyone who has been offered "senior" and "junior" money and wants to understand the difference. Senior debt vs subordinated debt comes down to ranking: senior debt is repaid first and usually holds first-ranking security, while subordinated debt has agreed to be repaid only after the senior lender, so it carries more risk and is normally priced higher and structured more flexibly. Smart Funding Solutions is a broker, not a lender. We arrange business and property finance from around £10,000 to £500,000+, with larger facilities available in suitable cases, including layered structures through our structured finance work.

01What is senior debt?

Senior debt is borrowing that ranks ahead of all other lenders and shareholders for repayment, normally backed by first-ranking security over the borrower's assets. If the business fails or the property is sold, the senior lender is paid out first from the proceeds of the assets it holds security over.

Senior debt is usually the largest and cheapest layer of a funding structure because it carries the least risk. Typical examples include a bank or specialist lender's term loan secured by a debenture, a first-charge commercial mortgage, or the main facility in an acquisition. Senior lenders tend to impose the tightest conditions: regular reporting, financial covenants, and restrictions on further borrowing, dividends and asset sales.

02What is subordinated debt?

Subordinated debt, also called junior or sub debt, is borrowing that ranks behind senior debt, either because the lender has agreed to wait or because its security is second-ranking. It is still debt rather than equity, so it ranks ahead of shareholders, but it is paid only after the senior lender's position is satisfied.

Because the subordinated lender stands further back in the queue, it is more likely to lose money if things go wrong. To compensate, subordinated debt is usually priced higher and may include features such as interest that rolls up rather than being paid monthly, repayment in a single amount at the end, or a share in the upside. Forms of subordinated debt include second-charge loans, mezzanine finance, vendor loans in business sales, and loans from shareholders or directors that have been formally postponed.

03The capital stack explained

The capital stack is the full set of funding layers in a business or project, ranked from the safest, repaid first, to the riskiest, repaid last. Risk and expected return rise as you move down the stack.

Layer	Ranking	Typical security	Risk to the provider	How it is usually rewarded
Senior debt	First	First fixed and floating charges, or first legal charge on property	Lowest	Interest and fees, the lowest in the stack
Subordinated or second-lien debt	Second	Second-ranking charges, subject to an intercreditor agreement	Moderate	Higher interest, sometimes rolled up
Mezzanine finance	Behind senior and often other junior debt	Junior charges, or none beyond contractual rights	Higher	Higher interest, often with a profit share or equity option
Shareholder and vendor loans	Usually postponed to all external lenders	Often unsecured	High	Interest if and when paid, plus the owner's wider interest in the business
Equity	Last	None	Highest	Dividends and growth in value

Not every deal has every layer. Most small business borrowing is senior debt plus the owners' equity. Layers are added when the senior lender will not lend enough on its own and the owners do not have, or do not want to commit, the extra equity. Our guide to debt versus equity funding covers the bottom of the stack.

04How ranking works in practice

Ranking is set by a combination of security, contract and corporate structure, and it matters most when a business is sold, refinanced or becomes insolvent. There are three main ways one debt ends up behind another.

Security ranking

A lender with a first fixed charge over an asset is paid from that asset's sale before a lender with a second charge. Floating charges, which cover changing assets such as stock and debtors, rank in their own order and behind certain other claims on insolvency. Our guide to debentures and fixed and floating charges explains the mechanics.

Contractual subordination

Lenders sign an intercreditor agreement or deed of priority setting out who is paid first, what the junior lender can and cannot do, and when it can receive payments. Typically, the junior lender agrees not to take enforcement action without the senior lender's consent for a period, and may be blocked from receiving payments if the senior debt is in default. Directors who have lent money to their company may be asked to sign a similar postponement letter.

Structural subordination

In a group, a lender to a holding company stands behind lenders to the trading subsidiary, because the holding company's only asset is its shares in the subsidiary. Lenders deal with this through guarantees and security from the subsidiaries, which is why acquisition finance documentation often includes cross-guarantees across the group.

The capital stack is the full set of funding layers in a business or project, ranked from the safest, repaid first, to the riskiest, repaid last.

05What happens on insolvency

On insolvency, the proceeds of a company's assets are distributed in a statutory order of priority, and the senior lender's first-ranking security means it is usually among the first to be paid from the assets it holds. In broad terms, fixed charge holders are paid from fixed charge assets, then the costs of the insolvency and preferential creditors (which can include certain employee claims and some HMRC debts) are met, a portion of floating charge realisations may be set aside for unsecured creditors, and then floating charge holders, unsecured creditors, subordinated creditors and finally shareholders follow. The detail is technical; the Insolvency Service publishes guidance.

Illustration only. A hypothetical company is bought for £1,000,000, funded by £600,000 of senior debt, £200,000 of subordinated debt and £200,000 of the buyers' equity. Some years later, trading collapses and the business and its assets are sold for £700,000 after costs and prior claims. The senior lender recovers its full £600,000. The subordinated lender receives the remaining £100,000, half of what it is owed. The equity holders receive nothing. Had the sale raised £500,000, the senior lender would have lost £100,000 and the subordinated lender would have recovered nothing.

£150,000A transaction we arranged£150K requirement. Two repayment structures. One solution.We split the facility: £78,000 repaid over five years and £72,000 interest-only, so repayments fitted how the business runs.

06Senior debt vs subordinated debt: the key differences

The key differences between senior and subordinated debt are ranking, security, cost and flexibility. The table compares them from a borrower's point of view.

Feature	Senior debt	Subordinated debt
Repayment priority	First	After senior debt
Security	First-ranking	Second-ranking or none
How costs are structured	Lower interest margin, arrangement fee	Higher interest, often rolled up, sometimes an exit fee or equity share
Repayment profile	Usually amortising monthly or quarterly	Often interest-only or a single payment at the end
Covenants	Usually the tightest	Often looser, but restricted by the intercreditor agreement
Typical share of funding	The largest layer	A smaller top-up layer
Main purpose	Core funding	Bridging the gap between senior debt and equity

07When businesses use subordinated debt

Businesses use subordinated debt when senior lenders will not stretch far enough and the owners want to avoid putting in, or giving away, more equity. Common situations include:

• Acquisitions and buyouts, where the price exceeds what senior lenders will provide against profits and assets. See management buyout finance.
• Vendor finance, where the seller leaves part of the price outstanding. Senior lenders almost always require it to rank behind them; our guide to vendor finance and deferred consideration explains how.
• Property development, where mezzanine tops up senior development finance to reduce the developer's cash input. See property development finance.
• Growth and refinancing, where a business needs more than its senior lender will provide and a private debt or direct lending fund can provide a junior or stretched layer.

08What senior and junior lenders each assess

Senior and junior lenders look at the same business but ask different questions, because they lose money in different scenarios. A senior lender wants confidence that its debt is repaid even in a poor outcome; a junior lender needs the business to perform reasonably well for its money to come back in full.

Senior lenders focus on asset values, security cover and affordability measured with ratios such as the debt service cover ratio, and usually size their facility so it is comfortably covered. Junior lenders look harder at the total debt the business will carry, measured through leverage and the other financial ratios lenders use, as well as the quality of management, the business plan and how and when they will be repaid, often from a sale or refinance. Expect both to ask for the same core documents: accounts, management accounts, forecasts and, in a purchase, the due diligence reports. In an acquisition, the junior lender will also want to see the senior terms before agreeing its own.

09Pros and cons of adding a subordinated layer

A subordinated layer can make a deal possible, but it adds cost, complexity and a second lender with its own rights. Weigh both sides.

• Pro: borrows more than senior lenders alone would provide.
• Pro: preserves ownership compared with raising new equity.
• Pro: repayment can be structured around cash flow, for example interest rolling up until a sale or refinance.
• Con: higher cost than senior debt, and rolled-up interest compounds.
• Con: legal costs and time for intercreditor documentation.
• Con: more lenders to keep informed, and more covenants to manage.
• Con: on a weak outcome, equity is squeezed harder because more debt ranks ahead of it.

10How Smart Funding Solutions can help