Can a Head Contractor Withhold Payment for Variations?

Variations are one of the most common sources of payment disputes between head contractors and subcontractors. When a subcontractor performs additional work — work that wasn’t in the original contract — the head contractor is obligated to pay for it. But can a head contractor legally withhold payment for variations? And what are your rights if they do?

What Is a Variation?

A variation (or variation order) is any change to the scope of work from what was originally contracted. This includes additional work, changes to materials or specifications, redesign requirements, or work caused by unforeseen site conditions. Variations are extremely common on construction projects — particularly on residential renovations and commercial fit-outs where designs change during construction.

Can a Head Contractor Withhold Payment for Variations?

A head contractor can legitimately dispute a variation claim in certain circumstances:

• No valid variation instruction: If the variation wasn’t actually instructed by someone with authority to direct variations under the contract
• Scope dispute: Genuine disagreement about whether the work was part of the original scope or an additional variation
• Pricing dispute: Disagreement about the rate or amount charged for the variation
• Contract terms: Some contracts require variations to be approved in writing before they’re performed — if you performed the work without written approval, the head contractor may dispute entitlement

However, “can dispute” is very different from “can simply withhold without explanation.” Even where a variation is disputed, the head contractor must formally state the dispute in a payment schedule — they cannot simply ignore your invoice.

The Verbal Instruction Problem

The most common variation dispute scenario: a site supervisor tells you verbally to do additional work. You do it. You invoice for it. The head contractor’s accounts team has no record of the instruction and refuses to pay.

This is frustrating but not hopeless. Under Security of Payment law, you can claim for variations — including verbally instructed variations — in your payment claim. The adjudicator will assess the evidence: your site diary, text messages, emails, photos, and witness statements. Verbal instructions are not automatically disqualified, but you need evidence that the instruction was given by someone with authority.

How to Protect Yourself on Variations

• Get instructions in writing: Even a text message or email from a site supervisor is valuable evidence
• Confirm verbal instructions immediately: After receiving a verbal direction, send an email confirming what was instructed and by whom
• Keep a site diary: Record every instruction, change, and additional work on a daily basis
• Photograph additional work: Photos with timestamps show what work was done and when
• Submit variation notices promptly: Many contracts require variation notices to be submitted within a set time — know your contract requirements

Claiming Unpaid Variations Under the SOP Act

You can include disputed variations in your Security of Payment claim. When the adjudicator receives your claim and the head contractor’s payment schedule, they’ll assess whether the variation was genuinely instructed and what the appropriate payment is. Adjudicators are experienced construction professionals who understand how sites work — including how verbal instructions happen in practice.

PayClaim helps subcontractors present variation claims effectively, including gathering and organising evidence to support the claim. Start your free claim today.