Close is 6 weeks out. Payroll, bank signatories, customer letters and the org chart for the morning after all need an owner. If nobody on your team has run an integration, hire a consultant for that window.
Hire them to run the integration office, not to make the decisions. The consultant runs the calendar, the Day 1 plan and the synergy tracker. Your executives still pick the leaders, set the structure and own the numbers. GAO's merger guidance puts day-to-day management with a dedicated implementation team that top leadership gives the authority to act.
Skip the hire if the target will run as a standalone business, or if you have an experienced integration lead who can do it full time.
What they do
An integration consultant turns the deal thesis into a plan, a governance structure and a weekly rhythm, then keeps both companies on it.
Before close. They set up the integration management office, define workstreams such as finance, HR, IT, sales and operations, and write the Day 1 plan: what must work the morning after close, from payroll to customer letters. When buyer and target compete, they work under clean team rules. The FTC says the parties must keep operating independently until closing, and that information shared for integration planning should be narrowly tailored. It names third-party consultants and clean teams as safeguards.
After close. They run the integration calendar, track synergies against the deal model, manage dependencies between workstreams, take open decisions to a steering committee, and run communication and retention plans for key people.
What they do not do. They do not own the decisions or the results. GAO's merger guidance says a dedicated implementation team should give the merger "focused, full-time attention," with authority from top leadership to set priorities and make timely decisions. Executives GAO interviewed said its members should have prior merger experience and program management skills. A consultant supports that team. It does not replace it.
When to hire, and when not to
Hire when
- The target adds a large share of your revenue or headcount, and you have never integrated a company of that size.
- Nobody inside has run an integration before, and close is weeks away with no Day 1 plan.
- Buyer and target compete, so pre-close planning must run through a clean team, with a third party handling sensitive data.
- The deal model depends on cost or revenue synergies that someone must track line by line against a baseline.
- A private equity sponsor is building a platform through add-ons and wants a playbook built once and reused on each deal.
Skip it when
- The target will run as a standalone business under its own management, and integration is limited to financial reporting and controls.
- You have an experienced integration lead who can work on it full time. Give that person authority and a budget instead.
- The work is one functional project, such as moving the target onto your ERP or payroll. Hire a specialist in that system.
- You want someone else to make the hard decisions on structure and leadership roles. A consultant can frame them. Your executives must make and announce them.
How engagements are set up
Pre-close planning project
Runs from signing to close and can be priced as a fixed fee. Delivers integration governance, workstream charters, the Day 1 plan, the clean team protocol and the synergy baseline. Fits buyers who will run the rest themselves.
Integration office support
A small consultant team runs the integration office next to your internal lead, billed monthly or by day rate. Fits deals where several workstreams must move at once. One talent marketplace lists typical engagements of 6 to 18 months, from pre-close planning to delivery.
Interim or fractional integration lead
One senior person acts as your integration leader for a fixed term, part time or full time, then hands over to an internal lead. Fits mid-market deals where a full team is more than the work needs.
Workstream specialist
Covers one function only, such as IT, finance or HR integration, and reports into your own integration office. Fits buyers who can run the program but lack depth in one area.
Playbook build for serial acquirers
The consultant documents your process, templates and checklists over 1 or 2 deals so your own team runs the next ones. Fits PE platforms and companies with an acquisition program.
What it costs
Ask each firm to price in one of three ways.
Fixed fee for a scoped phase, such as pre-close planning through Day 1. Time-based, as a day rate per named person or a monthly fee for the team, with a cap. Partly tied to synergies, only if the baseline and the measurement method are written into the contract first.
Ask for the fee by phase, the named person behind each rate, and what happens to the fee if close slips.
Before you talk to firms
- The deal thesis on 1 page: why you bought, what must not break, and the synergy targets in the deal model.
- The purchase agreement, closing conditions, expected close date, and any transition services agreement.
- A named internal integration lead with authority and protected time, and a steering committee that will meet weekly.
- A list of key people at the target you must keep, and the retention budget.
- Antitrust counsel's view on what can be shared before close, if the companies compete.
- An integration budget separate from the consultant fee, covering severance, systems and retention payments.
Questions to ask in the pitch meeting
- How many integrations have you personally led in the last 3 years, at what deal size, and can I speak to the CEO or CFO on 2 of them?
- Who exactly will work on our deal, how many days a week each, and what does the contract say if a named person leaves?
- What is on your Day 1 checklist, and which items have you seen fail?
- How do you build the synergy baseline, and who signs off that a synergy has been realized?
- How will you run pre-close planning within antitrust rules? Have you worked under a clean team agreement?
- Which parts of this business would you integrate quickly, which would you leave alone, and why?
- Which decisions must we make in the first 30 days, and which can wait?
- How many hours a week will our managers spend on integration, and who should be our full-time integration lead?
- What will you hand over when you leave, and how will we run the remaining work without you?
- Describe an integration that went badly. What did you change afterward?
Warning signs
- The partner who pitched will not be on the work, and the day-to-day team has not run an integration.
- A standard 100-day plan arrives before they understand the deal thesis. A study of 99 deals found fast integration of people helped performance, while fast integration of tasks hurt it.
- They expect to own decisions on structure and leadership roles that belong to your executives.
- Synergy tracking is a list of initiatives with no baseline, no owner per line, and no link to the P&L.
- They propose sharing pricing, customer or strategy data between competing parties before close without counsel and a clean team.
- Fees grow by adding junior staff for status reporting, not by closing open issues.
- They have no plan for communication, culture, or keeping the people you bought the company for.
Frequently asked questions
When should we bring in an integration consultant?
At signing, before close. In a survey of more than 800 executives summarized in 2015, delays and lack of preparedness were key reasons integrations failed, and a smooth transition from closing correlated highly with success. The FTC allows integration planning before close, but the parties must keep operating independently until closing. Shared information must be narrowly tailored, and competitors should use a clean team.
How long does an integration engagement last?
One Australian talent marketplace lists typical engagements of 6 to 18 months, from pre-close planning to integration delivery. Length depends on how much you integrate. Combining financial reporting and controls takes less time than moving the target onto your systems, sales model and organization. Agree the handover to an internal lead before the engagement starts.
Should we integrate as fast as possible?
Not everything. A 2015 study of 99 deals by acquirers in German-speaking Europe found that fast integration of people helped performance, while fast integration of tasks hurt it. A 2004 paper on the first 100 days warned against accepting the benefits of speed without question. Move fast on leadership appointments, communication and retention. Sequence systems and process changes.
What is an integration management office?
It is the small team that runs the integration program. It sets the calendar, tracks workstreams and synergies, manages dependencies, and takes open decisions to a steering committee. GAO's merger guidance says top leadership must give this team the authority and resources to set priorities and make timely decisions. A consultant can staff or support it. The decisions stay with your executives.
Can our diligence advisor also run the integration?
Yes, and it already knows the deal. Diligence and integration need different skills. Diligence tests a thesis before signing. Integration runs a program across every function after close. Ask for integration references specifically, meet the integration team rather than the deal team, and check that the people who built the synergy case are not the only ones judging whether it was met.
Sources
- GAO-03-669, Results-Oriented Cultures: Implementation Steps to Assist Mergers and Organizational Transformations (2003)
- FTC Bureau of Competition, Avoiding antitrust pitfalls during pre-merger negotiations and due diligence (2018)
- DealLawyers.com, summary of a post-merger integration survey of more than 800 executives (2015)
- Uzelac, Bauer, Matzler and Waschak, The moderating effects of decision-making preferences on M&A integration speed and performance, International Journal of Human Resource Management (2015)
- Angwin, Speed in M&A integration: the first 100 days, European Management Journal (2004)
- Post-merger integration consultant engagement types and lengths, Australian talent marketplace (checked October 2026)
Written by Stratrix editors from public sources and checked claim by claim by a second AI model. Firms pay Stratrix when they accept an introduction; they do not pay to influence this guide, and it names none of them. How introductions work