Variation approvals on WhatsApp: message templates, legal points and a simple workflow featured image
Business & Operations

Variation approvals on WhatsApp: message templates, legal points and a simple workflow

TrainAR Team 24 days ago 7 min read

Variation approvals on WhatsApp: message templates, legal points and a simple workflow

Category: Business & Operations • Niche: WhatsApp workflows, contracts, applications for payment, automations

Contents

Site supervisor confirming a variation on WhatsApp with clear approval wording

Who this is for

  • Small to mid-size contractors and trades who already use WhatsApp with clients or site teams.
  • Businesses that want variations agreed quickly without losing the audit trail you need to get paid.
  • Office managers who reconcile applications for payment and want clean evidence attached.

Related reading in the Academy:

Quick answer

Yes, you can get valid variation approvals over WhatsApp if you make the key terms clear and you keep the evidence. A recent High Court case confirmed that construction contracts can be formed by WhatsApp messages where offer, acceptance, price and intention are present. See law firm summaries of Jaevee Homes v Fincham and the judgment for details.

This article gives you practical wording, a simple workflow, and how to attach the approval to job costing and your next application for payment.

  • A message thread can be a binding contract if the basics are there: a clear offer, a clear yes, a price and the intention to be bound. The court in Jaevee Homes v Fincham found a construction deal agreed over WhatsApp was binding, even though a formal subcontract was never signed. See the judgment and commentary from Kennedys and Forsters.
  • If you do not want a chat to be binding, say “subject to contract” clearly at the start. If you want the approval to be binding, avoid that phrase and ask for a plain acceptance message.
  • Payment timing and mechanics can be filled in by statute where needed. In Jaevee, “monthly applications” in messages were enough to run the payment cycle. If you use applications for payment, make sure variations appear in the right month and that notices are served on time.
  • This is general guidance, not legal advice. If in doubt, get your contract admin reviewed by a construction solicitor.

The simple WhatsApp-first variation workflow

Follow these nine steps. They are fast for site teams and give you an audit trail that stands up later.

  1. Set your rules and authorisation
  • Decide who in your business can approve or send variation quotes on WhatsApp and set a value limit that needs an office double-check.
  • Agree a numbering format per job, for example Job 4786 variation V-003.
  1. Capture the change with clear context
  • Get a quick photo or short video, and write one sentence describing the change and why it is needed.
  • If the client requested it, keep their original message in the thread.
  1. Price it properly and state VAT and programme impact
  • State the price including whether VAT applies, any labour hours, and any time impact on the programme.
  • If a call-out or abortive visit is involved, price that separately.

  1. Send the variation quote message Use the template in the next section. Make the acceptance easy and unambiguous.

  2. Get explicit acceptance

  • Ask the client to reply with the exact acceptance line so the approval is crystal clear. Avoid vague thumbs up emojis alone.
  1. Save the evidence
  • Export the WhatsApp chat to PDF or save screenshots. File it in the job folder under Variations with the number you chose.
  1. Update job costing and schedule
  • Add a new variation line in your job system with the same V number so accounts can find it.
  • Adjust your task dates if the change affects the programme.
  1. Add it to the right application for payment
  • If you do monthly applications, include the variation in the next valid cycle and reference the WhatsApp approval in your evidence pack.
  1. Trigger payment on completion or milestone
  • For small variations, send a payment link immediately on completion. See our guide to pay by bank links for fast, low-fee collection.

Copy-and-send message templates

You can paste these into WhatsApp Business as quick replies and edit the bits in brackets.

  1. Variation quote to a client

“Variation [V-0XX] for [Job/Address].

  • Scope: [add 1 extra radiator in bedroom 2, tie into existing 15 mm flow/return].
  • Price: £[420] plus VAT.
  • Programme: [no delay to completion].
  • Payment: [due on completion of this variation].

To approve, please reply with: ‘I approve variation [V-0XX] for £[420] plus VAT on [today’s date].’”

  1. Client acceptance prompt

“Thanks. For our records, please reply exactly with: ‘I approve variation [V-0XX] for £[420] plus VAT on [DD/MM/YYYY].’”

  1. Subcontractor variation back-to-back

“Sub variation [SV-0XX] on [Project].

  • Scope: [detail].
  • Your price: £[amount] + VAT.
  • Evidence: send 2 photos when done. Reply: ‘I accept SV-0XX at £[amount] + VAT. I will complete by [date].’”
  1. Change declined

“Thanks for confirming. We will proceed without the variation [V-0XX] and keep the original scope.”

Automation options if you want to take it further

  • WhatsApp Business shared inbox. If more than one person handles variations, use a shared inbox so approvals do not get stuck on one phone. Popular options integrate a shared number, tags and quick replies.
  • Auto filing. Use an automation to export the WhatsApp message and attachments to a cloud folder named JobNumber/Variations/V-0XX so accounts can find it instantly.
  • Accounting and job systems. Create a matching variation line automatically in your job system so the office can include it in the next application. If you already run live margins from field to accounts, stick to the same naming scheme used in your job costing. For ideas, see: Build a live job margin workflow: Tradify to Xero or QuickBooks without double entry.

Common pitfalls and how to avoid them

  • Vague approvals. “Sounds good” is weaker than a clear sentence. Ask for the exact approval wording. Courts look at clarity.
  • Hidden “subject to contract.” If your email footer or template says this, it can conflict with your aim. Use clear language when you do intend to bind.
  • Wrong application period. If you are on monthly applications, include the variation in the right month. In Jaevee, one invoice failed because it fell in the wrong monthly window. See the judgment.
  • Consumer jobs. For domestic customers, keep your standard terms consistent with consumer law and give any required pre-contract information. Variations should not strip cancellation rights where they apply. Take advice if unsure.
  • Data protection. WhatsApp contains personal data. Restrict access, avoid sharing card details in chat, and export only what you need for the job record.

FAQs

Can a WhatsApp message be a binding approval for a variation?

Yes, if the essentials are there: clear offer, clear acceptance, price and intention to be bound. The High Court confirmed a construction deal formed over WhatsApp in Jaevee Homes v Fincham. See Osborne Clarke and the judgment.

Do I need a signature or can I rely on a reply?

A typed reply with the right wording can be enough. Ask the client to reply with the exact sentence in the template so there is no doubt. Keep the thread export as evidence.

Is a thumbs up emoji enough?

Emojis can be risky because they can be vague. Prefer a sentence that repeats the key terms. If the client only s…