You've seen the listing: a retiring owner, forty clients, steady MRR, and a price that looks like a steal. Before you sign anything, you need to know whether that revenue is real. Diligence on contracts, margins, and concentration is the difference between a good deal and a money pit.
Here's the plain answer: audit the book before you bid. Pull the client list, the contracts, and the billing history. Ask the seller to show you renewals and churn. Then compare each client's pricing against your own service cost model. If the seller can't produce accurate contracts or billing data, walk away.
Picture a client that looks profitable on revenue alone: fifty users, a clean per-user rate, and a smile on the seller's face. Then you open the ticket history and find they average forty tickets a month, most of them for things your standard scope doesn't cover. That client is eating your margin in hours you'll never bill for.
What Are You Actually Buying?
Start with the data dump. Ask the seller for a list of every client, their contract, their billing history, and their ticket volume for the last twelve months. You need to see renewals and churn, not just current revenue. If the seller hesitates or gives you summaries instead of raw data, that's a red flag.
One owner who bought a similar book found that out of forty clients, only one was worth keeping. The rest were paying too little and demanding too much. They're planning to drop most of them. That's not an industry statistic, it's one person's experience, but it's the kind of outcome diligence is supposed to catch before you pay.
The first step is mechanical: get the data, put it in a spreadsheet, and sort it by revenue and by ticket count. Then read the contracts.
Contracts: Can You Keep the Clients?
A contract determines whether the revenue survives the ownership change. Check four things: assignability, notice period, auto-renewal terms, and service scope.
| What to check | Why it matters |
|---|---|
| Assignability | If the contract can't be assigned to you without client consent, you're renegotiating at acquisition time. |
| Notice period | A month-to-month client can leave the day the seller tells them about the sale. |
| Auto-renewal | Annual contracts that roll over give you a window of stability; month-to-month gives you none. |
| Service scope | Vague boundaries let clients demand more than the price covers. |
Take a client on a month-to-month contract. The moment they hear their trusted provider is being sold, they can give thirty days' notice and walk. You've paid for revenue that evaporates before you've onboarded anyone.
Scope creep is the quieter killer. A contract that says "IT support" without defining what's included means every printer, every personal device, every 'while you're here' request is yours to absorb. If you can't see what's in scope, assume the worst and price accordingly.
If contracts are non-assignable, plan for renegotiation or expect churn. Even with solid contracts, you still need to know if the pricing covers your cost model.
Margins: Does Pricing Fit Your Cost Model?
Which clients in the book are worth serving at your standard pricing? The answer comes from comparing each client's historical support cost to the revenue they generate. You need ticket volume, hours spent, and billing data. Without it, you're guessing.
Say you have a tiered pricing model: full per-user for full-time staff, a partial rate for contractors without PCs, and a separate per-endpoint charge. A legacy client paying flat per-user but generating high ticket volume from a handful of power users won't fit that model. The fix is either reprice them to a tier that matches their usage, or set a limited scope and bill hourly for anything beyond it.
You can't set this pricing at the sales stage. You don't know who will call until you've served them for a few months. So set a limited scope at the start and bill hourly for overage, then adjust after you have real support data.
Once you've sorted by margin, the next question is about the few clients that dominate revenue.
Concentration: What Happens If One Client Leaves?
Map revenue by client and stress-test the loss of the top one, two, or three. If any single client is more than a quarter of the book's revenue, you need a retention plan for that account specifically.
Picture a book where one client is 40% of revenue. The acquisition pays for itself only if that client stays. Lose them in month two and you've bought a liability.
You'll want to talk to those top clients early to gauge their loyalty. But be careful: contacting the seller's clients before closing can damage the deal and invite legal trouble if it breaches confidentiality obligations. Only approach them with the seller's cooperation and within the terms of your agreement.
Once you know which clients you need to keep, the next problem is making sure they stay after the seller leaves.
The Seller Handoff: How to Retain Clients After They Exit
Clients value the relationship, not the company. One tech who left an MSP found clients following him to his new shop, because they trusted him, not the logo. If the seller has that kind of relationship, you need them to hand it over personally.
Structure the deal so the seller has a reason to help. Tie part of the payment to retention: an earn-out or a phased payment where the seller gets paid for clients still under contract twelve months later. Sellers may refuse, and you should be ready for that. If they won't share the risk, lower your upfront offer.
During the transition, have the seller introduce you in person or on a call. Run joint meetings for the first month. Set a 30/60/90-day communication plan so every client hears from you before they hear it from someone else.
Even with a perfect handoff, some clients will leave or need repricing. What do you do with the ones that don't fit?
After the Deal: Keep or Drop, Reprice, and Rebuild
Within the first 90 days, review each client against your margin and service model. Drop or reprice the bottom feeders instead of letting them drain your team. The sooner you act, the better.
Repricing or dropping clients will cause some churn. That's fine. Clients who leave because you asked to be paid fairly weren't going to be profitable anyway. Communicate clearly: give legacy clients a grandfather period with a defined date when they move to your standard pricing, and make the terms explicit.
And if the book doesn't fit after diligence, walking away is a legitimate outcome. The best deal you'll ever make is the one you didn't.
On Monday, set up the client review spreadsheet and schedule the keep/drop meeting. The decision to buy a client book is also the decision to build your future practice. Do the math first, and you'll know which one you're actually making.
mspoutpost.com/articles/what-to-check-before-you-bid-on-a-book-of-clients
Written by Graham Whitfield
MSP Outpost publishes information, not legal, financial, insurance, tax or compliance advice, and reading it creates no professional relationship. For decisions about your business, talk to a qualified professional.
