What does a buy-side M&A adviser do, and is one worth it?

A buy-side M&A adviser works only for the company that is buying. Their job is to help you find the right business, test it hard, and complete on terms that protect you. Whether one is worth paying for depends on three things: the size of the deal, how much M&A experience you have in-house, and how much you stand to overpay without help.

This matters because most of the advisers you meet during an acquisition work for the seller: the broker who brought you the deal, the lawyer on the other side, the accountants who prepared the information memorandum. A buy-side adviser is the one person in the room whose job is to protect the buyer.

What is the difference between buy-side and sell-side advice?

Sell-side advisers are hired by the business being sold. Their job is to get the highest price and the best terms for the seller, usually by creating competition between buyers. They are doing exactly what they are paid to do.

Buy-side advisers are hired by the acquirer. Their job is to find the right target, assess it critically and negotiate terms that protect the buyer, before completion rather than after.

Many firms say they can advise on both sides. On a single deal that is a conflict. A firm whose income mostly comes from selling businesses will find it hard to push back hard on a seller's price. We are buy-side only: we never act for sellers.

What does a buy-side M&A adviser actually do?

A full buy-side mandate runs from strategy to completion. Not every buyer needs every stage, but here is what each one involves.

Acquisition strategy and thesis

Before anyone is approached, the adviser helps you write down why you are buying and what you are looking for. That is your acquisition thesis: sector, size, geography, financial profile, management, and walk-away rules.

Walk-away rules are the most important output of this stage and the one most often skipped. Without them, criteria bend under deal pressure. A price that was too high becomes acceptable. Customer concentration that was a red flag becomes "something to fix after completion".

Target origination

Finding the right target is the work most buyers underestimate. The businesses worth buying are often founder-led, profitable and not thinking about selling. Those same qualities keep them off broker lists.

A buy-side adviser researches the whole target universe, then contacts owners directly. Each conversation is qualified against your criteria, so your leadership team only sees businesses that have already been assessed. Our guide to finding off-market acquisition targets in the UK explains the method.

Approach

How you first contact an owner shapes everything after it. A good adviser writes the approach, makes the first contact, and handles early conversations so the owner is not put off and you are not exposed too early. Many owners will talk to an independent adviser more freely than to a competitor.

Valuation

The adviser builds an independent view of what the business is worth, using more than one method, and tests whether the seller's price is defensible. They also look at what the business is worth to you, including synergies you should not pay the seller for.

Negotiation and heads of terms

This covers the structure of the offer (cash, deferred consideration, earn-out, vendor loan) and the heads of terms. Heads of terms set the shape of the deal before lawyers start drafting. They are the most important document in the process, and the one buyers most often underestimate.

Due diligence coordination

Financial, tax and legal due diligence are normally done by separate accountants and lawyers, paid separately. The buy-side adviser scopes the work, keeps it to time, and makes sure findings are judged against the original thesis, not explained away to keep the deal alive.

Completion

The adviser works with your lawyers so the sale and purchase agreement reflects what was agreed at heads of terms. They also track the issues that tend to reopen price late on, such as working capital, debt and conditions.

How are buy-side advisers paid in the UK?

Most buy-side advisers combine a fee for their time with a success fee paid on completion. The main models are:

• Monthly retainer. A fixed monthly fee while the work runs. In a 2023 survey of 199 European M&A advisers, the most common monthly fee was €5,000 to €10,000, and 32% charged €11,000 or more (Firmex).
• Fixed project fee. One agreed price for a defined scope and timetable.
• Success (completion) fee. A percentage of the deal value, paid only if the deal completes. In the same survey the average was 4.7% on a €5m deal and 1.7% on a €150m deal. 76% of advisers charged a minimum success fee.
• Lehman-style scales. The classic Lehman scale charges 5% on the first million, 4% on the second, 3% on the third, 2% on the fourth and 1% above that. "Double Lehman" doubles those rates (Wikipedia). Firmex found 49% of European advisers use a Lehman-type scale. One UK adviser, Capital A, publishes a buy-side scale running from 5% down to 1% over £4m (Capital A).

The Firmex survey does not split buy-side from sell-side fees, so treat these as market context rather than a buy-side price list. Our full breakdown is in buy-side M&A fees in the UK.

Why pay a fee for time at all? An adviser paid only on completion earns the same whether the deal is right or wrong. The time-based fee pays for honest advice at the moments when the right answer is "walk away".

How we charge. Our 90-Day Acquisition Project is a fixed fee, agreed before work starts. Your target universe is mapped and agreed by week 3. By day 90 you have at least 5 serious sellers at your table, or we keep approaching at no extra fee. We work for one client per target market at a time. After day 90 there is no retainer; support through to completion is agreed per deal and paid only if you complete.

When is a buy-side adviser worth it, and when isn't it?

The honest test is simple: does the adviser's total fee look small next to the money they are likely to save you, or the deal you would not otherwise find?

A worked illustration

This is an illustration, not a forecast. The multiples below are assumptions chosen to show the arithmetic, not market data.

Assumptions

• The target makes £1.5m EBITDA a year.
• Bought off-market, through a direct approach, you agree a price of 5.0x EBITDA: £7.5m.
• The same business sold through a broker-run auction, with several bidders, goes for 6.0x: £9.0m.
• Your adviser charges a time fee of £50,000 (an assumption for the illustration) plus a success fee on the classic Lehman scale: 5% on the first £1m, 4% on the second, 3% on the third, 2% on the fourth and 1% above that.

The arithmetic

On these assumptions, the fees are earned back if the off-market route saves about 0.15x EBITDA (£225,000 ÷ £1.5m). Whatever structure you're offered, run the same sum: total fees against the price difference you expect.

Is the auction gap real? The evidence is mixed. A study of 575 acquisitions found auctions were linked to higher target returns than negotiated deals, most strongly for small targets (Schlingemann & Wu, 2015). That research covers listed companies, not owner-managed UK firms, so treat it as direction rather than proof.

When it is usually worth it

• You have no way to reach off-market targets that are not on broker lists.
• Your team has not run a deal before and needs senior support on valuation, heads of terms and diligence.
• The deal is time-sensitive and your managers cannot step away from running the business.
• You need independent challenge, because the board has fallen for one target.

When it usually isn't

• The deal is small and simple. If you are buying a £300,000 business, a typical adviser's fee could be more than 10% of the price. A good accountant and solicitor, plus your own preparation, may be enough. Our Acquisition Accelerator is built for owners who want to run the process themselves with structure and support.
• You already have an experienced M&A team with its own deal flow. You may only need help at one stage.
• The deal is already agreed and you just need it papered. That is a job for lawyers and accountants.

Buy-side adviser vs business broker vs corporate finance house vs head of M&A: which do you need?

A broker can still bring you good deals. Just remember who is paying them. Brokers' own retainers have drawn criticism: a 2019 AccountingWEB article reported sellers paying £30,000 to £50,000 upfront and receiving no serious buyer interest (AccountingWEB).

Due diligence is a separate cost whichever route you choose. For UK mid-market deals of £20m to £100m, one UK guide puts buy-side due diligence fees at £500,000 to £2m (FD Capital).

What should you ask before you hire a buy-side adviser?

Use this checklist in your first meeting. A good adviser will answer every question plainly.

• [ ] Do you ever act for sellers? If yes, how do you handle conflicts in my sector?
• [ ] Who will actually do the work? Will the partner I am meeting lead it, or hand it on?
• [ ] What exactly will I get, and by when? Ask for milestones in writing, not just a monthly fee.
• [ ] What happens if you miss them? Is there a guarantee, a pause or a break clause?
• [ ] How is the success fee calculated? On what value, at what rates, and is there a minimum?
• [ ] Does your fee rise if I pay more? A fee that grows with price can reward overpaying. Ask how they protect against that.
• [ ] Is there an abort or break fee if I walk away?
• [ ] Are retainers deducted from the success fee?
• [ ] Will you work for a competitor buying in the same market at the same time?
• [ ] Which deals like mine have you done? Ask for examples you can discuss in detail.
• [ ] What is not included? Legal, financial and tax due diligence are usually extra.
• [ ] Is VAT on top? Most quoted fees exclude it.

If you want to talk through whether an adviser makes sense for your deal, see how our buy-side advisory works, or start with the fees guide above.