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X8

Undertakings to the Client or Others

Reviewed by LazyQS Editorial·Last reviewed: 2026-02-19

Plain English Explanation

X8 (introduced in NEC4) requires the Contractor to provide undertakings to the Client and to third parties (Others) as stated in the Contract Data. These undertakings are direct obligations that sit alongside the main contract. They may include obligations to provide information, maintain records, comply with specific standards, or provide access to the Client or third parties.

X8 is a more structured mechanism than collateral warranties — it defines the scope of the Contractor's obligations to specific named parties in the Contract Data rather than requiring separate warranty documents. It is used to manage relationships with funders, tenants, statutory bodies, and other stakeholders.

In NEC4 terms, X8 replaces some of the functions that were previously handled through collateral warranty requirements.

Key Takeaway

X8 undertakings create direct obligations to named third parties — identify who those parties are at tender, assess the legal and insurance implications, and price accordingly.

What This Means for Subcontractors

Subcontractors may be required to provide similar undertakings under their subcontract. Review the Contract Data carefully to understand what undertakings are required and to whom they are owed. Undertakings can create direct obligations to third parties, which can have significant legal and commercial implications.

Common Risks & Disputes

  • 1Undertakings being required to parties you are not aware of at tender stage
  • 2The scope of undertakings being broader than anticipated, creating obligations beyond the subcontract works
  • 3Undertakings creating limitation period exposure beyond the standard contractual terms
  • 4Failure to pass undertaking requirements down into sub-subcontracts where relevant
  • 5The cost and insurance implications of undertakings not being priced into the bid

Sources

  1. NEC4 ECC Secondary Option X8— NEC4 ECC
  2. RICS Guidance Note: Third-Party Undertakings and Collateral Obligations in NEC4— RICS
  3. Fenwick Elliott: Undertakings to Third Parties Under NEC4 X8— Fenwick Elliott

Related Clauses

X4

Parent company guarantee

Parent company guarantee — another direct obligation providing security to third parties

X13

Performance bond

Performance bond — a related form of third-party security obligation

Continue Learning

Category Overview

Back to X Clauses (Secondary Options)

Adjacent Clauses

X7 Delay damagesX9 Transfer of rights

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