Post Merger Integration Checklist Day 1 to 100
Private Equity
Business Transformation
Case Studies
A post merger integration checklist is useful only if it drives owners, dates, and proof. Day 1 needs business continuity. Day 100 needs stable operating cadence, clean reporting, and measurable value capture.
This checklist is written for leaders who want a single timeline from Day 1 through Day 100, plus workstream lists you can assign the same day.
Quick Answer
Day 1 to Day 100 integration succeeds when three things are true. Owners are named. Decisions are logged. Evidence exists for what changed and why.
Use the timeline checklist below to set the minimum bar for continuity, then use the workstream lists to assign tasks with dates and proof.
Internal reading.
Day 1 Readiness Checklist.
Mergers Acquisitions Services.
Change Management.
How to use this checklist
Do not treat this like a to do list you read once. Use it as an assignment tool.
For every item you keep, add an owner, a due date, and a proof link.
Minimum setup in 60 minutes
- Name an Integration Lead and a deputy.
- Stand up an IMO tracker with owners and dates.
- Create a single Decision Log for Day 1 through Day 100.
- Define the top ten continuity risks and the owner for each.
- Agree on weekly reporting format for leaders.
Definition of done by Day 100
- Day 1 continuity risks closed or controlled.
- Operating cadence stable and owned.
- Combined financial reporting cadence stable.
- Key systems access stable and monitored.
- Value capture tracking active with owners and dates.
Timeline checklist: Day 1 to Day 100
The timeline below is organized by outcome, not by department. If an item does not apply, delete it.
If an item applies, assign it to a named person and link the proof.
| Time window | Outcomes | Checklist | Proof to store |
|---|---|---|---|
| Day 1 | Continuity and control | Publish Day 1 comms to customers and staff. Lock authority limits for spend, pricing exceptions, and credits. Confirm helpdesk, escalation, and on call list. Confirm access rules for key systems. Freeze high risk changes for 72 hours unless approved. | Comms pack. Authority matrix. On call roster. Access audit report. Freeze notice and exception approvals. |
| Days 2 to 7 | Stabilize operations | Run daily issue triage. Resolve top continuity gaps. Confirm top customer accounts and outreach owners. Stand up integration tracker and decision log. Confirm legal entity guardrails for contracting and data sharing. | Issue log. Customer outreach list. Tracker link. Decision log entries. Legal guardrail memo. |
| Days 8 to 30 | Integrate the operating rhythm | Stand up IMO cadence. Define workstreams and owners. Set synergy hypotheses and owners. Align reporting calendar. Confirm HR data, payroll, benefits, and policy differences with a plan and dates. Confirm IT identity approach and admin controls. | IMO charter. Workstream RACI. Synergy register. Reporting calendar. HR plan. IT identity plan. |
| Days 31 to 60 | Standardize core processes | Align core process owners and KPIs. Standardize quote to cash handoffs. Align procurement and vendor controls. Begin data mapping for key reports. Run first control checks for access and privileged roles. Update training for changed processes. | Process owner map. KPI list. Updated SOPs. Data mapping notes. Access review evidence. Training completion logs. |
| Days 61 to 100 | Close gaps and lock value capture | Close or replan open work with leadership decisions. Run a Day 100 readiness review. Confirm run state owners for processes and systems. Update the integration plan into a run plan. Validate synergy tracking and corrective actions. | Day 100 review deck. Run plan. Owner list. Updated budget impacts. Synergy results and corrective actions. |
Internal reading.
Post Merger Integration.
PMI Strategy and Execution.
Workstream checklists
Use these lists to assign owners by function. Keep only what fits your deal thesis and risk profile.
If you need a smaller starting point, assign the bold items first and set due dates within seven days.
Customers and go to market
- Customer comms. One message, one FAQ, and an escalation path for Day 1.
- Account ownership. Top accounts list, named owners, outreach dates.
- Sales rules. Discount limits, approvals, quoting tools, credit rules.
- Brand rules. Domains, signatures, naming, collateral refresh plan.
- Pipeline hygiene. CRM access, duplicate removal, stage definitions.
People and HR
- Org clarity. Interim org chart, decision rights, reporting lines.
- Retention risk. Top talent list, retention actions, manager scripts.
- Payroll and benefits. Cutover plan, employee communications, support mailbox.
- Policy mapping. Differences list, interim rules, adoption plan.
- Training plan. Role based changes, completion tracking.
Finance
- Day 1 cash control. Signatories, payment approvals, bank access.
- Close calendar. Combined reporting dates, owners, dependencies.
- Chart of accounts mapping. Interim mapping, long term target.
- Revenue recognition review. Deal specific risk items and controls.
- Working capital plan. Receivables, payables, inventory controls.
IT and data
- Identity plan. Access model for Day 1, joiner mover leaver rules.
- Privileged access. Admin roles review, break glass process, logging.
- Tool inventory. Critical apps list, owners, renewal dates.
- Data sharing guardrails. What is allowed now, what requires approvals.
- Integration roadmap. Sequencing, outages plan, support plan.
Legal and compliance
- Contracting authority. Who can sign what on Day 1.
- Regulatory notifications. Filing list, owners, due dates.
- Policy alignment. Code of conduct, privacy, security policies.
- Third party review. Key vendors, change of control clauses, remediation plan.
- Litigation and claims inventory. Known issues, owners, reporting cadence.
Operations and supply chain
- Continuity plan. Critical suppliers, backup plans, contact lists.
- Quality controls. Process changes review, approvals, audit plan.
- Facility plan. Site roles, access, signage plan.
- Inventory rules. Counting, write offs, reorder policies.
- Safety plan. Incident reporting, training, escalation.
Internal reading.
Cybersecurity Data Privacy.
Risk Management.
Meeting cadence and reporting
Cadence is what turns checklists into action. Keep meetings short and decision focused.
Use one leader report and one owner log, not multiple decks.
| Cadence | Attendees | Purpose | Outputs |
|---|---|---|---|
| Daily for Days 1 to 7 | Integration lead, workstream leads | Issue triage and continuity risks | Updated issue log, owner actions |
| Weekly for Days 8 to 100 | IMO, workstream leads | Progress, risks, cross team dependencies | Updated tracker, decision requests |
| Every two weeks | Sponsor, executive team | Decisions, tradeoffs, value capture review | Decision log updates, replan approvals |
| Monthly | Finance, sponsor | Value capture and budget impacts | Synergy report, corrective actions |
Internal reading.
Business Change Office.
Setting Up a PMO.
Copy templates
These templates match the checklist above. Copy, paste, and assign owners.
Store links to proof inside the same row so audits and leadership reviews are fast.
Decision log
Decision: Date: Decision owner: Context: Options reviewed: Decision made: Impacted workstreams: Actions: Owner: Due date: Proof link:
Integration tracker row
Workstream: Outcome: Task: Owner: Start date: Due date: Status: Dependency: Risk: Proof link:
Value capture register
Value item: Type: Baseline: Target by Day 100: Owner: Key actions: Dependencies: Risks: Measurement method: Weekly actual: Corrective action: Proof link:
Day 100 readiness review
Area: What is stable: What is not stable: Owner: Fix plan: Due date: Proof link: Leader decision needed:
External reading
These resources are useful to compare formats and task coverage. Use them as input, then run one integrated plan with a single owner log.
FAQ
What is the difference between Day 1 and Day 100 in PMI
Day 1 is about continuity, access, authority limits, and communications. Day 100 is about stable ownership, stable reporting, stable operating cadence, and measurable value capture.
Do we need an IMO
If the deal touches many workstreams, an IMO is the simplest way to keep owners, dates, dependencies, and decisions in one place. Keep the IMO small and use one tracker.
What should we track every week
Track continuity risks, overdue tasks, decisions waiting on leaders, and value capture items with owners. Track proof links for items that auditors or boards will ask about later.
