Photo Invoicing on WhatsApp — UK Tradesperson Guide

A lot of UK tradespeople still write job sheets on paper. The fitter who scribbles parts and labour into a notebook between jobs; the gas engineer who takes a customer's details on the back of a Wickes receipt; the decorator who photographs the agreed quote on a torn-off page from a notepad. Paper is fast in the moment — but it's also where invoices die because typing it all up at the kitchen table on Sunday night is too much friction.

Photo invoicing on WhatsApp closes that gap. Snap a photo of the handwritten job sheet, send it to Wedge on WhatsApp, and AI extracts the customer name, job description, parts list, and amount — generating a branded PDF invoice and sending it to the customer before you leave the property. This guide covers what works reliably, what trips it up, and the practical workflow.

What the AI can read reliably

Modern vision models (Claude vision, GPT-4 vision) read printed text near-perfectly and handwritten text well enough that almost any legible job sheet works. Things they read reliably:

• Block-capital customer names and addresses
• Standard numerical amounts written in pounds and pence
• Common job descriptions written as bullet points or short phrases
• Materials lists in any format (bulleted, comma-separated, or one-per-line)
• Phone numbers, postcodes, dates in standard UK formats

What can trip it up

• Extremely sloppy handwriting where individual letters bleed into each other
• Amounts written without a currency symbol or decimal point (£3.50 vs 350 vs 3 50)
• Customer names that look like job descriptions ("Mrs Davies bathroom" — is Davies the customer or the location?)
• Multiple jobs on one sheet with no clear separator — the AI may merge them into one invoice
• Carbon-copy receipts with bleed-through showing the layer below

Wedge handles ambiguity by showing you a preview before sending. If the AI's interpretation looks wrong, you reply to correct it in plain English: "No, the customer is Davies, the job was a bathroom refit." The corrected version regenerates in seconds.

The practical workflow

1. Finish the job. On the customer's drive or before getting back in the van, take your usual handwritten job sheet (or write a quick one on a scrap of paper).
2. Open WhatsApp. Find the Wedge contact in your chat list.
3. Snap a photo of the sheet — make sure the whole sheet is in frame, lighting is decent, no glare. Send the photo to Wedge.
4. Wedge replies in under 30 seconds with an extracted summary: 'Invoice for Mrs Davies — £1,840 for bathroom refit. £1,200 labour, £640 materials. Send this invoice?'
5. If correct, reply YES. If wrong, reply with the correction in plain English. Wedge regenerates and asks again.
6. Wedge generates the branded PDF, sends it to Mrs Davies via WhatsApp with a Stripe payment link, and adds it to your dashboard.

When photo invoicing makes the biggest difference

Photo invoicing is most valuable for tradespeople who:

• Do multiple smaller-ticket jobs per day (handymen, plumbers on call-out rotation, electricians on landlord call-outs) — typing each invoice takes longer than snapping a photo
• Already use paper job sheets and aren't going to switch to a structured digital form mid-career
• Have older customers who agreed pricing on paper that the tradesperson then needs to reproduce on a proper invoice
• Work in gloves, dust, or wet conditions where typing on a phone is awkward
• Need to invoice the customer-supplied detail (a parts list the customer wrote, a specification the customer drew) without retyping it

Materials lists from supplier receipts

A related pattern: snap a photo of the Wickes / Toolstation / Plumbase receipt and Wedge logs each line item as a separate expense entry in the right HMRC category. Useful for tradespeople who want clean expense records without typing them up at year-end. This isn't photo invoicing — it's photo expense tracking — but the workflow is the same.

Limitations to keep in mind

Photo invoicing isn't magic. Two limitations worth knowing:

1. VAT treatment can be ambiguous from a paper sheet. If the job needs reduced-rate (5%) VAT, zero-rated treatment, or CIS reverse-charge, mention it explicitly in your WhatsApp reply after sending the photo. The AI defaults to standard 20% VAT for VAT-registered tradespeople if the photo doesn't clearly indicate otherwise.
2. Customer contact details need to be on the sheet or in your existing customer history. If the photo shows only a first name and no contact info, Wedge will ask 'Which Dave? Is this the one at 14 Acacia Avenue?' — searching your customer history first before asking you to clarify.

The single biggest cash-flow change

Most UK tradespeople who switch to photo invoicing report that their cash-flow improves by 1-2 weeks within the first month. The reason isn't anything sophisticated about the AI — it's that invoices actually go out the same day the job is done. Same-day invoices pay faster than next-week invoices, and Friday-afternoon invoices pay vastly faster than 'I'll do it Sunday night' invoices that never happen.