WOPA

Key Features

• •Natural language invoice creation: Message your job details in plain English like 'invoice chris £850 rewire' and WOPA instantly drafts a professional invoice. No forms or templates to fill — just type and send. This saves time and matches how tradespeople naturally communicate.
• •Preview and confirm before sending: WOPA shows a complete draft with customer, amount, due date, and bank details. Nothing is sent until you reply 'YES'. This ensures accuracy and prevents mistakes, giving you full control over every invoice.
• •Email PDF invoice to customer: Once confirmed, WOPA emails a clean A4 PDF invoice directly to your customer with your business details and bank information. Your customer receives a professional-looking invoice without needing any special software.
• •Automatic payment reminders: WOPA sends polite payment reminders at 7, 14, and 28 days after the invoice is sent. Reminders are sent by email to your customer on your behalf, reducing the need for manual follow-ups and helping you get paid faster.
• •One-message bulk chasing: Type 'who hasn't paid?' to see all overdue invoices, then send 'chase both' to trigger reminders for all late payers at once. This makes it easy to manage multiple outstanding invoices from a single chat message.
• •Mark paid from WhatsApp: Simply type 'dan paid' to mark an invoice as paid. WOPA immediately stops all future reminders for that invoice and updates the status. This keeps your records accurate without additional data entry.
• •VAT, CIS, and construction reverse charge support: WOPA handles VAT, CIS deductions for subcontractors, and reverse-charge VAT for construction work. This makes it suitable for UK tradespeople who need to include these fields on their invoices.

Use Cases

• •Quick on-site invoicing: After finishing a job, a tradesperson types the job details into WhatsApp. WOPA drafts, confirms, and emails the invoice within 30 seconds — no need to return to the office. Outcome: faster invoice delivery and less admin time.
• •Bulk chasing overdue payments: A tradesperson asks 'who hasn't paid?' to see a list of late invoices. They then send 'chase both' to automatically email polite reminders to all overdue customers. Outcome: reduces the awkwardness of manual chasing and improves cash flow.
• •Marking payment received from chat: When a customer pays, the tradesperson simply types the customer's name and 'paid' to update the invoice status. Reminders stop automatically. Outcome: keeps records current without extra steps.
• •Sending invoices with VAT and CIS details: A subcontractor creates an invoice including CIS deduction and reverse-charge VAT by specifying the job in plain English. WOPA handles the tax fields correctly. Outcome: compliant invoices without complex calculations.
• •Checking outstanding amounts at a glance: Tradesperson messages 'who hasn't paid?' and receives a summary of total outstanding and which customers are late. Outcome: instant visibility into cash flow without logging into a dashboard.

Who is this for?

UK tradespeople including electricians, plumbers, carpenters, builders, painters and decorators, roofers, HVAC technicians, and landscapers. Also sole traders and small limited companies that manage their own invoicing. The tool is designed for those who want to send invoices quickly from their mobile phone without learning new software. Additionally, the Making Tax Digital early access feature invites landlords and accountants to provide feedback on future MTD compatibility. WOPA's primary audience is any UK tradesperson who already uses WhatsApp and seeks a simpler invoicing process.