WhatsApp Business Cloud connection fails with Error 400 – Resource not found

Questions
,
1

:bullseye: What is your goal?

I need to complete the registration of my existing WhatsApp Business phone number and successfully connect it to WhatsApp Business Cloud in Make.

:thinking: What is the problem & what have you tried?

Meta successfully completes the embedded signup and confirms the connection. However, after clicking “Finish”, Make displays “Resource not found”, followed by Error 400: “Failed to verify connection.”

The connection is not saved in Make Credentials. In Meta Business Manager, the WhatsApp Business Account and phone number exist, but the number remains in “Pending” status. Meta asks me to register the number through the Registration API or contact the technology partner.

I first created the WhatsApp Business Account and phone number through Make. I then repeated the process by selecting the existing account and existing phone number, but the same error occurred.

:clipboard: Error messages or input/output bundles

Error 1:
Resource not found

Error 2:
Error 400: Failed to verify connection.

Meta phone-number status:
Pending

Meta message:
Register this phone number with the registration API or contact your technology partner to register it.

:camera_with_flash: Screenshots (scenario flow, module settings, errors)

Errores.pdf (154 KB)

4

Hi Erwin,

The useful clue is that Meta completes the signup, but the phone number remains Pending. That suggests the WABA and phone number exist, but the final registration or verification step is not completing.

Since you already retried using the existing assets, I would check two things before repeating the setup again:

  1. Did you select Regular or Coexistence when creating the Make connection?
  2. Has this phone number previously been connected to another provider, CRM, inbox, or Meta business portfolio?

If it has, check Meta Business Settings > Accounts > WhatsApp Accounts > Partners. A previous partner can still retain access even when the number appears under the correct WABA. In that case, removing the partner or migrating the number may be required.

If there is no previous partner, I would stop recreating the WABA. Capture the WABA ID, phone number ID, connection mode and exact failure time, then send those to Make Support. Meta is completing its part, so the failure would be happening during Make’s final verification.

Can you confirm which connection mode you selected and whether that number was ever used with another provider? That should separate a migration conflict from a failed embedded signup.

5

Hi Zay,

Thank you for your response.

I selected Regular mode, not Coexistence.

The phone number was new and had never been connected to another provider, CRM, shared inbox, or Meta business portfolio.

Meta completes the signup successfully, but after clicking “Finish,” Make displays “Resource not found,” followed by Error 400: “Failed to verify connection.” The connection is not saved in Make Credentials, and the phone number remains Pending in Meta.

I will verify Meta Business Settings → Accounts → WhatsApp Accounts → Partners to confirm that no partner has access.

Thank you for your help.