M&A Synergy Realization Checklist

Pull the cost and revenue synergy schedule out of the deal model before it goes stale. Walk it line by line with the CFO and the corp dev partner who underwrote the deal — synergy claims that survived diligence often shrink in execution, and you need the named owner for each one before Day 30.

Translate each deal-model synergy into specific GL account codes and quarterly run-rate targets. Avoid the "$50M cost synergy" line item with no GL trail — finance can't track what isn't booked. Tag accounts with a class or dimension so the synergy report rolls up automatically each close.

Sequence finance, HR, IT, and customer workstreams into Day 30, 60, 90, and 100 milestones with named owners. Identify dependencies — for example, the first combined close depends on COA harmonization, which depends on policy reconciliation. Publish to the steering committee before Day 14.

Send a short anonymous survey covering close cadence, review depth, tolerance for AJEs, remote vs. in-office norms, and decision speed. Finance cultures diverge sharply on materiality thresholds and review intensity — surface those gaps before the first combined close, not during it.

Compare close calendars, AJE thresholds, partner-review depth, and tolerance for estimates. A target that closes in 5 business days with light review will resist moving to a 10-day partner-reviewed close — name the gap explicitly so leadership can decide rather than letting friction simmer.

The acquirer's controller and the target's controller jointly present the combined finance org chart, close calendar, and Q1 reporting cadence. Skip the platitudes — staff want to know who their manager is, when the new close happens, and whether their job is safe.

Document each side's AP cycle (three-way match, approval thresholds, payment cadence), AR cycle (billing trigger, collections cadence, write-off authority), payroll provider and deposit schedule, and close calendar. Side-by-side in one workbook so duplicates and gaps are visible at a glance.

Match by EIN, then by name and address. Same vendor under two records will fragment 1099 totals at year-end and produce duplicate IRS filings. Pull a fresh W-9 for any vendor where the legal name or EIN is ambiguous before the merged file is locked.

Set baseline and 90-day targets for DSO, DPO, close cycle days, and bank-rec turnaround on the combined entity. The deal model assumed working-capital improvements — make those concrete with operational KPIs the controller can move, not just headline ratios.

Decide whether to adopt the acquirer's COA, the target's COA, or build a new unified COA. The right answer depends on which entity has the better account hierarchy, dimension structure, and cleanliness — not which one is bigger. Map every legacy account to the target before any GL data migrates.

Compare revenue recognition (ASC 606), capitalization thresholds, depreciation methods, inventory costing, lease classification (ASC 842), and stock-comp policies. Document any GAAP-conforming changes and quantify the cumulative-effect adjustment to opening retained earnings. Run policy choices past the audit firm before booking.

Build the close calendar for the first combined period: who owns each lead schedule, when sub-ledger tie-outs are due, when AJEs are cut off, when partner review happens. Plan to close 1–2 days slower than steady state and pre-warn the audit committee — the first combined close is not the time to optimize.

Same enterprise customer often shows up in both ledgers under different parent/sub identifiers. Consolidate by EIN and contracting entity so AR aging, credit limits, and revenue concentration disclosures roll up correctly under the combined entity.

If one entity bills Net 30 and the other Net 60, decide the post-merger standard and grandfather existing contracts. Don't surprise customers with a unilateral terms change mid-contract — that's the fastest way to spike DSO and torch the synergy assumption.

Send remit-to changes, new W-9, and updated contracting entity to every customer in writing. AR teams that skip this step spend Q1 chasing payments that landed at the wrong lockbox. Coordinate with sales so customer-facing reps aren't blindsided.

List every system in scope: NetSuite, Sage Intacct, QuickBooks, Bill.com, Ramp, ADP, Gusto, Avalara, Fathom, Vena. Note license counts, renewal dates, and integration footprint. Surface duplicate-tool spend that becomes a Day-30 cost synergy.

Choose between migrating one entity to the other's GL, replacing both with a new platform, or running parallel through fiscal year-end. Migrations during a live close cycle fail; plan the cutover for the start of a fiscal period and lock historical data in the legacy system as read-only.

Schedule the cutover for the first day of a fiscal period. Run two closes in parallel for at least one month — opening balances tie, then validate that trial balances reconcile to the penny before going single-system. Coordinate with the audit firm so testing scope reflects the migration.

Map both entities' health plans, 401(k) match formulas, vesting schedules, PTO accrual, and payroll provider (Gusto, ADP, Paychex, Rippling). 401(k) plan merger requires a formal plan amendment, blackout period notice, and IRS filing — the timeline is longer than people expect, plan for 6–9 months.

Map the merged finance org: who reports to the CFO, single controller or two regional controllers, where AP/AR/payroll specialists land, who runs FP&A. Identify role overlaps that drive cost synergy and key-person risks where the only person who knows the target's revenue-rec process is leaving.

Align comp bands by role and geography. If the target paid 15% above market and the acquirer paid at market, decide whether to level up the acquirer's bands, freeze target comp, or grandfather. Document the choice with HR and the comp committee — surprises here drive senior-staff attrition in Q2.

Walk the combined org chart with tax counsel: parent, subsidiaries, disregarded entities, foreign entities. Draft or update intercompany services, licensing, and cost-sharing agreements before the first close that books intercompany activity — retroactive transfer-pricing documentation invites IRS scrutiny.

If the parent is an SEC issuer, the target's controls fall under SOX 404 scope at the next 10-K. If the target was private with limited ICFR documentation, you have months — not years — to bring controls up to issuer standard. Confirm with the audit committee and external auditor.

Run end-to-end walkthroughs on the target's order-to-cash, procure-to-pay, payroll, and close cycles against the acquirer's control matrix. Document key controls, identify gaps, and remediate before the auditor's interim testing window. The PCAOB inspections cycle has been brutal on first-year integrated audits — get ahead of it.

Combine both entities' state-by-state revenue and transactions to test economic-nexus thresholds (typically $100K or 200 transactions post-Wayfair). The combination often trips nexus in 5–10 new states overnight. Pull the Avalara or TaxJar nexus report on combined data, not each entity alone.

Register for sales-tax permits in newly-triggered states, plus any state UI/withholding registrations for newly-located employees. Look into voluntary disclosure agreements (VDAs) for any state where the target had unregistered nexus pre-deal — VDAs typically cap lookback at 3–4 years versus full lookback under audit.

Map audiences and cadences: board (monthly), audit committee (quarterly + ad hoc), employees (weekly all-hands first 30 days, then bi-weekly), customers (event-driven), vendors (event-driven), lenders (per credit agreement). Pre-clear messaging with legal and IR if public.

One page: synergy capture vs. plan, top three risks, decisions needed from the committee this week, milestones hit and missed. Resist the urge to expand into a 20-page pack — the committee wants signal, not noise.

Walk the audit partner and tax advisor through purchase accounting (ASC 805), opening balance sheet, policy changes, and ICFR scope changes. Surface estimated audit fee impact early — a missed conversation here turns into a fee surprise at year-end.

Name a single integration management office lead with calendar authority across functions and a synergy tracker owner who maintains the model. Without a dedicated owner, synergy tracking dies on Day 45 when everyone returns to their day jobs.

Each month, pull actuals from the GL against the synergy model by initiative. Variance >10% to plan triggers a steering-committee review. Distinguish run-rate synergies (annualized) from realized P&L savings — the deal model speaks in run-rate; the auditor speaks in actuals.

Capture what worked, what slipped, and what to carry into the next deal. Hand off remaining workstreams (year-end close, audit, plan-year benefits) to functional owners with clear exit criteria — the IMO disbands, the work doesn't.