Anchored to UK statute. Last verified 21 June 2026. View source-of-record.

maduediligencechecklist.co.uk

The UK M&A Due Diligence Checklist

Honest workstream ranges

UK M&A due diligence fees


UK transaction-services firms quote per engagement. There are no published rate cards. The ranges below reflect ICAEW Corporate Finance Faculty market practice for sub-£20m EV deals; scale upwards for larger deals, regulated sectors and multi-jurisdiction tax structuring.

Direct answer

Total UK M&A due diligence on a sub-£20m EV deal typically runs £60-180k of adviser fees: legal £15-50k, financial DD £20-60k, tax DD £10-40k, optional commercial DD £25-100k and optional IT / cyber DD £10-40k. Big Four scope adds 1.5-2.5x at comparable mandate. W&I insurance, where used, is priced separately by the underwriter at 0.7-1.5% of cover.


By workstream

WorkstreamLowHighBasis
Legal due diligence£15,000£50,000Lead transaction solicitor + property + employment seats.
Financial DD (FDD)£20,000£60,000Tier-2 firm, scoped to QoE, working capital and net debt.
Tax DD£10,000£40,000CT, VAT, PAYE, ERS and tax-deed review.
Commercial DD£25,000£100,000Specialist boutique; in-house if the buyer has CDD capacity.
IT and cyber DD£10,000£40,000Application inventory, cyber posture, pen-test review.
Environmental (Phase I)£5,000£25,000Phase I ESA on each operational site. Phase II extra.
W&I premium (optional)£30,000£90,0000.7-1.5% of cover; underwriter-set, not adviser fee.

Estimator

Workstream fee estimator

WorkstreamLowHigh
Legal due diligence£14,000£45,000
Financial DD (FDD)£18,000£54,000
Tax DD£9,000£36,000
Commercial DD£23,000£90,000
IT and cyber DD£9,000£36,000
Indicative total£73,000£261,000

Indicative only. Every UK transaction-services firm quotes per engagement. Ranges scaled from ICAEW market practice; verify with a quote.

What moves the quote

  • EV size. Fees scale sub-linearly with EV: a £50m deal does not cost 5x a £10m deal but typically 1.5-2x.
  • Jurisdictions. Each additional tax jurisdiction adds 20-30% to tax DD scope and 10-15% to legal.
  • Regulated sector. FCA, CQC or Ofcom oversight typically adds 25-40% to legal and tax DD on top of dedicated regulatory DD.
  • Vendor co-operation. A disorganised data room and slow Q&A turn doubles the FDD partner's hours.
  • Carve-out vs trade sale. Carve-out FDD requires stand-alone-cost modelling, typically a 40-60% premium.
  • Big Four badge. Adds 1.5-2.5x at comparable scope. Justify only where IC, lenders or LPs will discount a Tier-2 deliverable.

Reviewed by Oliver Wakefield-Smith, Founder, Digital SignetLast verified 21 June 2026

This page is anchored to UK primary legislation and named regulator guidance only. Not legal advice. Confirm position with your appointed adviser before signing.