Contract Commencement

Contract commencement marks the point at which the supplier's performance obligations formally begin. It is a date-certain event that is agreed in the contract documents and governs the start of the contract duration, the delivery timeline, and the contract performance monitoring regime. Commencement and signature are related but separate events, and understanding the difference matters for mobilisation planning.

What is Contract Commencement?

The commencement date is the agreed start date for service delivery, works, or supply under the contract. It may coincide with the date of contract signature on short, straightforward contracts, or it may be set weeks or months later on complex contracts to allow for mobilisation, staff TUPE transfers, system integrations, or site preparation.

Contract documents typically specify commencement in one of two ways:

• a fixed calendar date (for example, "the Service shall commence on 1 January 2026"),
• a trigger-based date (for example, "the commencement date shall be thirty days after the date of contract execution").

Where an incumbent supplier is being replaced, the commencement date is usually coordinated with the expiry of the incumbent's contract to avoid gaps or overlaps in service. Failure to meet the commencement date is typically a breach of contract, and many public contracts include provisions for pre-agreed financial remedies or step-in rights if the supplier fails to mobilise on time.

For works contracts governed by standard European forms such as FIDIC or NEC, the start date (or the date for commencement of works) carries specific contractual meaning and triggers obligations on both the employer and the contractor.

Why it matters for bidders

Commencement planning is part of the bid: the mobilisation plan submitted in your tender will be evaluated and contractually incorporated. An unrealistic commencement date or an underestimated mobilisation period is a common cause of early contract difficulties. Winning bidders should immediately after contract signature initiate internal kick-off processes, TUPE consultation timetables, supply chain purchase orders, and system configuration activities so that the commencement date is met without incident.

Understanding the commencement date also matters for interim payments and milestone payments: many payment schedules are anchored to the number of months or milestones from commencement, not from signature.

Example

A Finnish municipality signs a waste collection contract on 15 November. The contract sets the commencement date as 1 February of the following year, giving the supplier seventy-seven days to recruit drivers, procure vehicles, and establish depot operations. Key mobilisation milestones at weeks four, eight, and twelve are monitored by the authority before the commencement date, with a right to terminate if the supplier cannot demonstrate readiness.

Frequently Asked Questions

What happens if the commencement date is missed?

Most public contracts include provisions for delay. A supplier that fails to achieve the agreed commencement date may be liable for liquidated damages, and the authority may have step-in rights allowing it to procure interim services at the supplier's cost. Prolonged delay may give the authority the right to terminate for cause.

Can the commencement date be moved after signature?

Yes, by mutual agreement between the parties. A contract variation or instruction under the contract's change management provisions can adjust the commencement date. However, both parties must agree, and unilateral delay by either party typically carries contractual consequences.

Is the commencement date the same as the mobilisation start date?

Not necessarily. Mobilisation often begins before the contract commencement date, sometimes authorised by a letter of intent. The commencement date is the date on which the supplier's delivery obligations formally begin and from which the contract duration is measured.