Variation confirmation letter template
Use this when a main contractor or their site team gives you a verbal or informal instruction to do work that isn't in your original scope. Confirm it in writing before you carry it out, and you protect your right to be paid for the extra work — and for any time it costs you.
When to use it
"Just crack on, we'll sort the paperwork later." Those words have cost subcontractors more money than almost anything else on site. Most subcontracts say a variation only counts if it's instructed in writing. Act on a nod and you're exposed: when the account is settled, the instruction is denied and the extra work becomes free work. A one-page confirmation, sent the same day, closes that gap.
What to include
- Who gave the instruction, and exactly when (date, time, place or call).
- A plain description of what you were told to do.
- A statement that this is a variation to the subcontract works.
- A request for a formal variation order and agreed valuation before you proceed.
- An express reservation of your right to additional time and cost.
- An invitation for them to correct you in writing if they disagree.
The template
[YOUR COMPANY NAME]
[Your address]
[Main contractor name]
[Their address]
[Date]
Dear [Name],
Re: [Project name / reference] — Confirmation of variation instruction
We write to confirm an instruction given to us by [name of person] of your
company on [date] [in person on site / by telephone / verbally], namely:
[Describe the instructed work as precisely as you can, e.g. "to relocate
the second-floor riser and re-run the associated pipework to the revised
setting-out issued on drawing ref XXX."]
This instruction changes the scope of our subcontract works and accordingly
constitutes a variation under [clause reference / the subcontract]. Before
proceeding, we request that you issue a formal variation order and that the
valuation of this variation is agreed in accordance with the subcontract.
We reserve our rights to claim an appropriate extension of time and to recover
the additional cost and any loss and expense arising from this variation.
If our understanding of the instruction is incorrect in any respect, please
notify us in writing by return so that the position can be corrected before the
works are carried out.
Yours faithfully,
[Your name]
[Your position]
[Your company]
This template is general guidance, not legal advice. Check the variation and notice provisions in your own subcontract, and take professional advice before relying on it in a live dispute.
Let Shield write it for you
Shield Index reads your project email as it arrives and flags the exact moment an instruction changes your scope — a variation trigger, a scope change, a verbal instruction referenced in a reply. It then drafts this confirmation with the names, dates and references already filled in, so it's ready to review and send in seconds. Every email is hash-stamped as evidence the instant it lands.
Common questions
Is a verbal instruction to do extra work valid?
Often yes in practice, but most construction subcontracts require variations to be instructed in writing. If you act on a verbal instruction without confirming it, you carry the risk: the main contractor can later deny it, and you may struggle to get paid for the extra work or the time it cost you. Confirming the instruction in writing converts a conversation into a documented variation.
What if they refuse to confirm the variation order?
Your confirmation letter still does its job. It puts your version of events on the record, dated and unanswered. If they genuinely disagree, they have to say so in writing — and if they don't respond at all, their silence sits alongside your letter as evidence. Never simply stop; follow your subcontract's dispute and payment procedures.
How quickly should I send it?
Immediately — ideally the same day, before you start the varied work. Sending it promptly removes any argument that you invented the instruction after the fact, and it gives the main contractor the chance to correct you in writing if they disagree.
Related templates
Delay notification letter Extension of Time (EOT) notice Late payment notice