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How to Send Invoice via WhatsApp / Email

One-click delivery of a posted invoice PDF.

4 min read Updated Jun 2026   How-To

Purpose

Send a posted invoice to the customer via WhatsApp or email, directly from the invoice screen, with the customer copy as a PDF attachment and a templated message body. Saves paper, settles disputes faster, and gives you a delivery log.

Before you begin

  • Invoice is posted (you can re-send any time after).
  • Customer master has a valid mobile number (for WhatsApp) or email (for email).
  • For WhatsApp: a messaging gateway configured under Communication & Integration (Msg91 / Twilio / etc.).
  • For email: SMTP configured under Communication & Integration.
  • A message template for invoice delivery in File Management → Message Templates.

Steps

  1. Open the posted invoice from Purchase & Sales → Sales Register.
  2. Click Send → pick WhatsApp or Email.
  3. The system pre-fills the recipient (from the customer master), the message body (from the template) and the PDF attachment.
  4. Edit the recipient or message if needed — for example to copy a procurement contact.
  5. Click Send. The gateway delivers the message and logs the result on the invoice as Sent / Delivered / Failed.
  6. For bulk re-send (e.g. month-end reminder), use Bulk Send from the Sales Register with a date / status filter.

What success looks like

  • The customer receives the message with the invoice PDF.
  • The invoice shows a delivery log entry with channel, recipient and status.
  • For WhatsApp, the customer's read receipt is logged once the gateway returns it.

Troubleshooting

Send button is disabled.
Either invoice is not posted, or no gateway is configured for that channel. Check Communication & Integration.
WhatsApp message bounces with "not opted in".
Customer has not opted in to your WhatsApp business number. Send a one-time opt-in via the gateway's onboarding flow.
Email goes to spam.
SPF / DKIM is not set for your sending domain. Coordinate with IT to add them.

Tips

  • Keep the message template short and include the invoice number — the customer's accounts team will quote it back.
  • Use bulk send sparingly on WhatsApp — gateways throttle and a sudden surge can get your number flagged.
  • Warning. WhatsApp delivery is a third-party gateway service — it can fail silently if your gateway credits are exhausted. Monitor the delivery log.