Invoice not sending

Clicking “Send” on an invoice produces an error or the customer never receives the invoice by email or SMS.

Why this happens

Stripe is not connected or the onboarding flow was not completed, so payment links cannot be generated.
The customer record has no email address or phone number saved.
SMS sending requires a Twilio account and an A2P (Application-to-Person) registration; either may be missing or incomplete.
The connected email integration lost its authentication and now shows “Needs Attention” in Settings → Integrations.

Go to Settings → Payments and check the Connect tab. If the status shows “Complete onboarding”, click Continue onboarding and finish the Stripe setup before retrying.
Open the customer record for the invoice recipient. Confirm that a valid email address is saved for email delivery, or a mobile phone number for SMS delivery. Add the missing contact detail and save.
For SMS failures, go to Settings → Phone Numbers. If you see “Twilio account not found” or “A2P registration not found”, click Create Twilio Account and complete the A2P registration steps before resending.
Go to Settings → Integrations and check the Email row. If the status shows “Needs Attention”, re-authenticate the integration, then retry sending the invoice.

If Stripe onboarding is complete but payment links still fail, check whether the invoice is still in Draft status. Only finalised invoices can be sent with a payment link.
If SMS is registered and the number is correct but the message is not delivered, note the error message shown after clicking Send and contact Servinix support with the invoice number and the error text.
Gather: the invoice number, the customer’s contact details, and a screenshot of any error shown in the portal.