Summary
Summary
- Regulatory review sets a fixed minimum for larger deals: 30 days for a US HSR filing, 40 working days for a UK CMA Phase 1 review, 25 working days for an EU Phase 1 review.
- Most deals never face an in-depth review. In FY2023, US agencies issued 37 Second Requests across 1,735 eligible HSR transactions, about 2.1%.
- For most mid-market deals the controllable delays matter more: an unprepared data room, disputes over the purchase agreement and key people being unavailable.
- Every week after exclusivity gives the buyer more time to find issues, and gives the market more time to move. Prepare before signing the LOI, not after.
01 · Research
Two clocks run on every deal
Once a letter of intent is signed, two clocks start. The first is fixed: statutory review periods set by competition and foreign investment regulators. Neither party can shorten them. The second is controllable: how long diligence, documentation and negotiation take. For most mid-market private deals, the second clock is the one that kills transactions.
Delay is dangerous for a simple reason. The buyer's confidence is highest at signing. Every additional week is a week in which diligence can surface something new, the buyer's financing or board priorities can change, market multiples can move and the seller's own trading can soften. None of those help the seller.
02 · Research
The fixed clock: statutory review timelines
Minimum waiting and review periods in the markets where we most often run mandates.
| Jurisdiction | Regime | Initial period | Extended or in-depth review |
|---|---|---|---|
| United States | Hart-Scott-Rodino Act (FTC and DOJ) | 30 days; 15 days for cash tender offers | Second Request pauses the clock until substantial compliance, then a further 30 days (10 for cash tenders) |
| United States | CFIUS (foreign investment) | 45 day review | 45 day investigation, with a further 15 days possible in exceptional cases |
| United Kingdom | CMA merger control | Phase 1: 40 working days | Phase 2: 24 weeks, extendable by up to 8 weeks |
| United Kingdom | National Security and Investment Act 2021 | 30 working day review of a notification | Assessment of 30 working days, extendable by 45 working days and further by agreement |
| European Union | EU Merger Regulation | Phase 1: 25 working days | Phase 2: 90 working days, extendable |
| Australia | Foreign Acquisitions and Takeovers Act (FIRB) | 30 day statutory decision period | Extendable by up to 90 days, or longer by agreement |
| Singapore | CCCS merger review (voluntary regime) | Phase 1: 30 working days | Phase 2: 120 working days |
In-depth reviews are uncommon. In fiscal year 2023, US agencies received 1,805 HSR filings, of which 1,735 were eligible for a Second Request, and issued 37 Second Requests, about 2.1% of eligible transactions. For the large majority of filings, the initial waiting period is the whole regulatory clock.
03 · Research
The controllable clock: why deals really slow down
- 01Data room not readyMissing contracts, unreconciled financials and unanswered diligence questions are the most common source of delay. Every request that takes a week to answer is a week of drift.
- 02Purchase agreement disputesRounds of redlines on warranties, indemnities, escrow and the working capital peg. These are faster when the headline terms were fixed precisely in the LOI.
- 03People unavailableFounders running the business while selling it, holidays, and advisers stretched across several deals. A single missing signatory can stall a closing.
- 04Trading surprisesA weak month during diligence invites the buyer to revisit price. The longer the process, the more months of trading the buyer sees.
04 · Research
The decay zones: deal risk by days since LOI
Acquiry process guidance for a typical mid-market deal with no in-depth regulatory review.
| Days since LOI | Zone | What is typically happening | Seller priority |
|---|---|---|---|
| 0 to 60 | Safe zone | Confirmatory diligence and first draft of the purchase agreement. Buyer conviction is at its peak. | Answer every diligence request within 48 hours |
| 61 to 90 | Danger zone | Exclusivity nears expiry. Diligence fatigue, new questions and first requests to revisit terms. | Close out open issues and fix a signing date |
| 91 and beyond | Kill zone | Exclusivity often extended under pressure. Retrade requests, financing and market changes compound. | Decide: close on current terms, or reopen the process |
We do not publish a percentage drop in completion probability per month because no public dataset measures it for private deals. The zones reflect where we see risk build on live mandates: around the end of the exclusivity window, when the buyer's leverage peaks and the seller's alternatives have gone cold.
05 · Research
How to keep a deal inside the safe zone
- 01Build the data room before the LOISell-side preparation moves weeks of work to before exclusivity, when it costs the seller nothing in leverage.
- 02Make the LOI specificFix the working capital peg method, escrow, earnout mechanics and key warranties at LOI stage. Our LOI Value Decoder shows what each term is worth.
- 03Keep exclusivity short and conditionalSixty days with a defined extension trigger keeps both sides working to a timetable.
- 04Run a weekly closing callOne owner of the issues list, one call a week, every open point assigned.
06 · Research
Methodology and sources
Statutory periods are summarised from the governing legislation and regulator guidance and are simplified. Filing thresholds, sector tests and procedural rules change and differ by transaction, so take legal advice on any specific deal. The decay zones are Acquiry process guidance.
- Federal Trade Commission and Department of JusticeHart-Scott-Rodino Annual Report, Fiscal Year 2023.
- UK Competition and Markets AuthorityMergers: guidance on the CMA's jurisdiction and procedure (CMA2).
- UK Cabinet OfficeNational Security and Investment Act 2021: guidance on notification and review periods.
- European CommissionCouncil Regulation (EC) No 139/2004 (EU Merger Regulation).
- Australian Treasury, Foreign Investment Review BoardForeign Acquisitions and Takeovers Act 1975 and FIRB guidance on decision timeframes.
- Competition and Consumer Commission of SingaporeGuidelines on merger procedures.
- US Department of the TreasuryCFIUS review and investigation periods under 50 U.S.C. 4565.
Reference
Frequently asked questions
How long does it take to close a deal after signing an LOI?
There is no fixed figure. A well-prepared mid-market deal with no regulatory filing can close within the exclusivity window, commonly 60 to 90 days. Deals needing merger control or foreign investment clearance are bounded by those statutory timelines, which can add months if an in-depth review opens.
What is the HSR waiting period?
Under the Hart-Scott-Rodino Act, parties to a reportable US transaction must file and wait 30 days before closing, or 15 days for cash tender offers and certain bankruptcy sales. The agencies can extend this by issuing a Second Request, which pauses the clock until the parties substantially comply.
How often do regulators open an in-depth review?
Rarely. In fiscal year 2023, the FTC and DOJ issued 37 Second Requests out of 1,735 transactions eligible for one, about 2.1%, according to the agencies' HSR annual report.
Does the UK require approval for tech acquisitions?
Possibly under two regimes. The National Security and Investment Act 2021 requires mandatory notification for acquisitions in 17 sensitive sectors, with a 30 working day review period that can extend by 30 and then 45 more working days. Separately, the CMA can review mergers, with a 40 working day Phase 1 deadline.
What are the most common causes of post-LOI delay?
An incomplete or disorganised data room, prolonged negotiation of the purchase agreement, and key people on either side being unavailable. All three are within the parties' control, unlike statutory review periods.
Does this report say how much deal probability falls per month?
No. There is no public dataset that tracks completion probability against days since LOI for private deals, so we do not publish a percentage. The zones in this report are Acquiry process guidance, not measured probabilities.




