The investment case for an add-on acquisition is usually written in a spreadsheet: combined EBITDA, shared-services savings, cross-selling, a higher multiple on the larger group. None of that happens at closing. It happens, or fails to, in the hundred days that follow, and it is decided less by the quality of the deal than by the quality of the integration plan and the person who owns it.
Before closing
Integration planning starts during diligence, not after. By the time the deal closes, the platform should have a written plan with a named integration owner, a mapping of the acquired company's systems and processes onto the platform's, a list of people decisions, a communication plan for customers, vendors and staff, and a day-by-day schedule for the first two weeks. If the plan cannot be written, the platform is not ready to acquire, which is the subject of the platform readiness note.
Week one: control and communication
- Cash and bank control. Signatories updated, payment approvals routed through the platform's process with dual control, and a daily cash view for the acquired business.
- Access. Administrative access to every system, domain, account and contract inventoried and secured. Personal accounts holding business assets identified.
- People. Every employee told in person what changes and what does not, who they report to, and when they will hear more. Key people spoken to individually.
- Customers and vendors. A short, honest communication that names the new ownership, confirms continuity, and gives a contact.
- The acquired founder. A written agreement on their role, authority and time horizon, revisited in person in week one regardless of what the contract says.
Month one: finance, people, systems
The acquired business moves onto the platform's chart of accounts and close calendar in the first month, even if its historical books stay in the old system for reference. Payroll and people records migrate to the platform's system of record. Vendors are matched against the approved list and consolidated where terms are better. The main operating system migration is scoped and scheduled, not necessarily executed: moving a customer-facing system badly in month one causes more damage than running two systems for a quarter.
Day one hundred: one basis, one review
By day one hundred the acquired business should appear in the platform's monthly management pack on the same basis as every other unit, with its own margin detail underneath. Its manager should attend the weekly operating review with numbers prepared in advance. Its core workflows should have named owners on the platform's process documents. The shared-services savings in the investment case should be visible as vacated cost, not as a plan. And the first quarterly plan should include the acquired business as a unit with priorities, not as a project.
| Horizon | Finance | People | Systems | Cadence |
|---|---|---|---|---|
| Week one | Bank control, daily cash | Everyone told, key people met | Access secured | Integration owner in weekly review |
| Month one | Platform chart of accounts, first close | Payroll and records migrated | Operating migration scoped | Unit manager in weekly review |
| Day 100 | In the consolidated pack, unit margin visible | Roles on platform documents | Operating migration under way or done | Unit in quarterly plan |
The mistakes that turn deals into distractions
- No named owner. Integration done by everyone is done by no one. One person owns the plan and reports on it weekly.
- Migrating the customer system first. The most visible system is the most dangerous to move early.
- Letting the acquired business keep its own back office. The synergy case assumes it will not. Every month of delay is a month the case is untrue.
- Ignoring the acquired founder. Their knowledge, relationships and mood determine whether staff and customers stay through the transition.
- Buying the next one before this one is integrated. Two half-integrated businesses are worse than one un-acquired one.
In the formula this site uses, enterprise value equals sustainable EBITDA multiplied by a market multiple, integration is what turns an acquisition's revenue into the group's EBITDA and what keeps the group's multiple intact. The Portfolios page describes the model in full; the shared services note describes the layer an acquired business joins.