Day 1 readiness checklist for M&A: customers, people, systems, legal, and comms

Day 1 readiness meaning

Day 1 readiness means you can operate safely and credibly the moment the deal closes. It is not “integration complete.” It is business continuity plus trust: customers get consistent service, employees know what changes and what does not, systems access is controlled, and legal and compliance guardrails are in place.

Related searches include: day 1 readiness checklist for m&a template, day 1 readiness checklist for m&a ppt, day 1 readiness checklist for m&a excel, day 1 readiness checklist for m&a pdf, and day 1 readiness meaning.

Sources: [S1], [S2], External: Deloitte, McKinsey

Day 1 readiness checklist: how to use it

A Day 1 readiness checklist works only if it is owner-based and date-based. One owner per line item. One due date. One dependency field. One sign-off point for Day 1 go-live.

1. Start with customers, systems access, and legal guardrails. These are the fastest ways to break trust on Day 1.
2. Convert decisions into tasks. Example: “Who can approve credits on Day 1?” becomes an access change plus a comms note.
3. Run a short readiness review cadence from sign to close. Track what is blocked and who can unblock it.
4. Confirm Day 1 roles and escalation. If something goes wrong, people must know who owns the decision in minutes, not days.

Sources: [S1], [S2], External: Deloitte, McKinsey

Internal support: PMI strategy and execution.

Customers: service guardrails and customer comms Day 1

Customer comms Day 1 is about continuity and confidence. Customers should know what stays the same, what changes, and how to get help fast. If you have key accounts, plan 1:1 outreach.

Customer guardrails (minimum set)

• Service continuity: hours, response targets, escalation path, and outage communication.
• Commercial continuity: how quotes, renewals, credits, refunds, and pricing exceptions work on Day 1.
• Brand and naming: how customers should refer to you and what logos and email domains are in use.
• Contract intake: who can sign what, and what must wait until legal integration steps are done.

Customer comms Day 1 checklist

• One customer message and a short FAQ.
• A contact path: a mailbox or hotline that is staffed on Day 1.
• A list of top accounts and owners for outreach.
• A list of customer-facing systems that must be stable (support portal, billing, status page).

Sources: [S3], External: HBR

Internal support: change management.

People: employee comms and operating decisions

Day 1 employee comms should reduce uncertainty while staying accurate. Say what you can confirm, what you cannot, and when the next update will come. Also confirm the minimum operating decisions so managers can run the business.

People decisions to lock for Day 1

• Who approves time, spend, discounts, credits, hiring, and terminations on Day 1?
• What changes immediately (or not): titles, reporting lines, compensation bands, benefits, and policies.
• Where employees go for answers: HR inbox, IT helpdesk, manager cascade.
• What the escalation path is for urgent issues.

Comms pack (minimum set)

• Day 1 note from leadership.
• Manager talking points and short FAQ.
• Employee FAQ focused on what changes on Day 1.
• Schedule for Day 1 to Day 2 updates.

Sources: [S3], [S6], External: HBR, McKinsey

Systems: access and security Day 1

Access and security Day 1 is where deals create avoidable risk. Decide who can access what on Day 1, then implement least-privilege access, logging, and a clean joiner-mover-leaver process for new roles and terminations.

Access and security Day 1 checklist

• Identity: which identity provider is used on Day 1 and how new users are onboarded.
• Accounts: a list of critical apps, shared accounts, and admin roles that must be reviewed.
• Privileged access: who has admin access and how it is approved and reviewed.
• Data handling: how data is shared across entities and what is blocked until approvals are complete.
• Monitoring: logs, alerting, and an incident contact list for Day 1.
• Offboarding: ensure terminated employees lose access immediately.

Sources: [S5], External: NIST SP 800-53

Internal support: cybersecurity and data privacy.

Legal: entity, contracts, and compliance

Legal Day 1 readiness is about what you can do now vs. what must wait. Confirm signature authority, contracting process, data processing and privacy constraints, and how you handle regulated activities during the transition.

Legal Day 1 checklist (common items)

• Entity and naming: legal entity names, invoice names, and who signs what.
• Customer and vendor contracting: who can approve, who can sign, and what language is required.
• Privacy: data sharing rules and customer notices when required.
• Disputes and escalations: who is on call for legal issues on Day 1.

TSA readiness

TSA readiness (transition services agreement readiness) is making sure the services needed after close are owned, measurable, and executable. If you rely on a TSA for IT, payroll, finance, or facilities, Day 1 readiness requires clear service definitions, contacts, and escalation.

TSA readiness checklist

• Services list and scope: what is provided and what is excluded.
• Service levels: response targets and outage handling.
• Governance: weekly review, issue tracking, and decision owners.
• Pricing and billing: how charges are calculated and disputed.
• Exit: a migration plan per service and an end date.

Sources: [S4], External: Deloitte

Templates: Excel, PPT, PDF

Use these as a day 1 readiness checklist for m&a template and then export to the format you need: day 1 readiness checklist for m&a excel, day 1 readiness checklist for m&a ppt, or day 1 readiness checklist for m&a pdf. Related keyword: post merger integration checklist xls.

Workstream,Item,Owner,Due date,Dependency,Status,Risk if missed,Proof of completion,Notes
Customers,Customer comms Day 1 message and FAQ,Name,YYYY-MM-DD,,Not started,Confusion and churn,Message approved and sent,
Customers,Escalation path and contact mailbox staffed,Name,YYYY-MM-DD,,Not started,Slow response,Mailbox monitored,
People,Day 1 leadership note to employees,Name,YYYY-MM-DD,,Not started,Low trust,Message sent,
People,Manager talking points and FAQ,Name,YYYY-MM-DD,,Not started,Mixed messaging,Pack distributed,
Systems,Day 1 access list for critical apps,Name,YYYY-MM-DD,,Not started,Security incident,Access review complete,
Systems,Admin access review and approvals,Name,YYYY-MM-DD,,Not started,Over-privilege,Approvals recorded,
Legal,Signature authority and contracting path,Name,YYYY-MM-DD,,Not started,Contract delay,Authority memo,
Legal,Privacy and data sharing guardrails,Name,YYYY-MM-DD,,Not started,Compliance breach,Approved guardrails,
TSA,TSA service list and contacts,Name,YYYY-MM-DD,,Not started,Operational disruption,TSA contacts confirmed,
          

Slide 1: Day 1 readiness summary (what will be stable on Day 1)
Slide 2: Top risks and mitigations (customers, people, systems, legal)
Slide 3: Customer comms Day 1 plan (message, owners, top accounts)
Slide 4: People comms plan (employee note, manager cascade, FAQ)
Slide 5: Access and security Day 1 (critical apps, admin controls, monitoring)
Slide 6: TSA readiness (services, owners, escalation, exit dates)
Slide 7: Day 1 vs. Day 2 (vs.) and 100-day plan milestones
Slide 8: Readiness tracker (owners, due dates, what is blocked)
          

To create a PDF:
1) Keep the checklist in one owner-based sheet.
2) Add a one-page summary (top 10 items, top 5 risks, Day 1 contacts).
3) Export to PDF with page headers showing version date and owner.
          

Sources: [S1], [S4], External: Deloitte, Deloitte TSA

M&A Day 2 and 100-day integration plan checklist (Excel)

Day 1 is continuity. M&A Day 2 is stabilization: fix what broke, close gaps in access and processes, and start the recurring integration cadence. A 100-day integration plan is where you push owned workstreams and measurable outcomes. Related keyword: 100 day integration plan checklist Excel.

Day 1 vs. Day 2 (vs.)

• Day 1: continuity, comms, access control, legal guardrails, TSA go-live.
• Day 2: stabilize operations, address gaps, confirm owners, start the weekly cadence.

Workstream,Outcome by Day 100,Metric,Owner,Top 3 milestones,Top dependencies,Top risks
Customers,Retention stable,Churn %,Name,Day 15 comms cadence; Day 30 service guardrails; Day 90 renewal playbook,CRM access,Customer confusion
People,Operating cadence stable,Manager participation %,Name,Day 10 manager cascade; Day 30 role clarity; Day 60 policy alignment,HR data,Attrition
Systems,Access controlled and stable,Privileged roles reviewed %,Name,Day 7 access cleanup; Day 45 logging standard; Day 90 IAM improvements,IT capacity,Security incident
Legal,Contracting stable,Cycle time,Name,Day 15 sign authority; Day 45 templates; Day 90 privacy review,Outside counsel,Approval delays
          

Sources: [S2], [S6], External: McKinsey, HBR

Sources

• S1. Deloitte, “M&A integration plan for Day one readiness” (integration checklist page). Accessed 2025-12-23. https://www.deloitte.com/us/en/services/consulting/articles/mergers-acquisitions-integration-plan-checklist.html
• S2. McKinsey & Company, “Equipping leaders for merger integration success.” Accessed 2025-12-23. https://www.mckinsey.com/capabilities/people-and-organizational-performance/our-insights/equipping-leaders-for-merger-integration-success
• S3. Harvard Business Review, “The Success of Your M&A Deal Hinges on How You Announce It.” Accessed 2025-12-23. https://hbr.org/2022/04/the-success-of-your-ma-deal-hinges-on-how-you-announce-it
• S4. Deloitte, “Recommendations for transition service agreement negotiations.” Accessed 2025-12-23. https://www.deloitte.com/us/en/what-we-do/capabilities/mergers-acquisitions-restructuring/articles/recommendations-for-transition-service-agreement-negotiations.html
• S5. National Institute of Standards and Technology (NIST), “Security and Privacy Controls for Information Systems and Organizations (NIST SP 800-53 Rev. 5)” (PDF). Accessed 2025-12-23. https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-53r5.pdf
• S6. Harvard Business Review, “A Guide to Building a Unified Culture After a Merger or Acquisition.” Accessed 2025-12-23. https://hbr.org/2025/04/a-guide-to-building-a-unified-culture-after-a-merger-or-acquisition
• S7. McKinsey & Company, “Post-close excellence in large-deal M&A.” Accessed 2025-12-23. https://www.mckinsey.com/capabilities/m-and-a/our-insights/post-close-excellence-in-large-deal-m-and-a