Buying one accounting firm in a year is a lot. Buying two? Most owners never try.
Dillon Business Advisors (DBA) did. In 2024, its leadership team decided acquisitions were the fastest way to grow the budget for director-level roles and give team members room to advance in their careers. By the end of 2025, the team had closed two deals.
Every deal is different, but the same principle held for both of DBA's: move quickly on internal communication and slowly on anything client-facing. Here's a 30/60/90-day plan built around that principle.
Integration starts well before anyone signs the closing documents. Due diligence is your best chance to learn how the other firm runs day to day, including what services it offers, how it bills, what software it relies on, and who clients call when they have a question.
As you go, get your definitions in writing. Terms like "monthly client" or "service package" sound universal, but one firm's monthly client might get full bookkeeping while another's simply pays monthly for an annual tax return. Sorting that out before the close saves a lot of confusion when you're trying to set up project, responsibilities, and pricing afterward.
If the seller is open to it, meet their team in person before closing so you can introduce yourself, walk through offer letters and the handbook, and answer questions face to face. Many buyers are surprised to learn this is fairly common — if not before the deal, then often within 30 days of the close. Meeting clients is a different matter, though, and it's best to wait until the deal is signed and funded.
It's also a good time to look at your own firm. If your technology can't handle more users, or your onboarding lives in someone's head rather than on paper, fix that first. Building the foundation while you're moving a new team onto it is much harder than having a stabilized foundation beforehand. beforehand.
For the first month, leave the acquired team's client work alone. Let them keep using the tools, processes, and routines they already know — with one exception: how your two teams talk to each other. You’ll want to get everyone onto the same messaging and meeting platform in the first week because nothing else in the plan works if internal communication isn’t set.
When DBA's second deal closed, the acquired team was using Google Workspace and Slack while DBA ran on Microsoft Teams. Relying on email to bridge the gap slowed everything down. It was a challenge, especially since the deal closed on October 1, just two weeks before the extension deadline.
Clarity is the next most pressing thing. Amy McCarty, DBA's Director of Operations, focused on helping the acquired teams understand "what is staying the same and what is changing," which goes a long way toward easing the uncertainty that comes with any ownership change.
This is also the time to rethink onboarding. A new hire usually starts with an open calendar and plenty of time to learn, but an acquired team member arrives with a full client load and deadlines of their own. DBA stretched its usual two-week onboarding over four to six weeks so training didn't come at the expense of client service.
Once the deadline pressure eases, you can start moving the acquired team onto your systems. That includes:
It helps to treat this move as a data security project as much as a technology one. You're shifting tax return data from one system to another, so make sure your written information security plan (WISP) covers the migration.
And expect some vendors to make consolidation easier than others. If combining accounts would require clients to re-enroll or sign new paperwork, it may make more sense to keep a separate account for a while. Confusing clients in month two isn't a good trade.
The long-term goal is one brand and one set of tools, so plan to turn off the acquired firm's old systems as soon as it's reasonable to do so without losing data.
If you can't cancel a subscription yet, drop it to the lowest tier with one or two admin logins instead of renewing seats for the whole team. Amy compares it to turning the hangers around in your closet: if no one touches the tool for a couple of months, you can be fairly confident you've moved everything you need.
Set a firm cutoff date, and check in with each person before you shut anything off. Otherwise, someone will likely keep using the old system until the day it disappears. On the bright side, eliminating duplicate subscriptions is one of the quickest ways an acquisition starts paying for itself.
Recurring revenue is a big part of what you bought, so be careful not to disrupt it in the first few months.
If the acquired firm's clients are drafted automatically, consider leaving the seller's payment processor in place for a while. DBA kept it running for three months, with an agreement for the seller to reconcile and forward deposits. Clients kept paying the same amount on the same day while DBA prepared new engagement letters, and everyone moved to DBA's billing system at the start of the new year.
An arrangement like that depends on trust between buyer and seller. If that trust isn't there yet, work out a clear process with your attorney before the deal closes.
If you're weighing an acquisition, or you've just closed one and the next 90 days already feel crowded, you don't have to work out the sequence on your own.
Collective by DBA's advisors have been through acquisitions and divestitures from both sides of the table. They can help you build an integration plan around your deal's timing, team, and technology, so small gaps get caught early — before they turn into lost clients or frustrated team members.
Schedule a call with Collective by DBA and ask for a copy of the integration timeline DBA uses with the firms it acquires.