Voicemail transcription no longer working — HTTP 403 from storage.googleapis.com

[Morgane]

Hello,

Infos :
v20.0.9.995 — engine 3CX, language fr-FR.
Since 2026-08-21 around 10:00 (+02:00), voicemails are emailed with the WAV but without transcription.

The upload of the audio file to your transcription bucket is rejected with HTTP 403.
Example — ext. 292, vmail_0781056340_292_20260821161018.wav, from 3CXGatewayService.log:

18:11:31.831 POST https://wmr.3cx.net/manager/requestaiconversion -> 200
18:11:31.873 PUT https://storage.googleapis.com/transcriber-eu/wav/b/1/*************....wav?*
18:11:31.935 Received HTTP response headers after 61.79ms - 403
18:11:31.935 [GoogleSignedUrlUploader] GoogleSignedUrlUploader returned Forbidden
18:12:30.933 Signed URL Upload attempt V174 2/3 -> 403 (same URL, same file)
18:21:31.815 Transcription timed out for 292/vmail_0781056340_292_20260821161018

This affects most voicemails (18 of 29 uploads failed on 21 Aug) across several extensions.
All requests to wmr.3cx.net return 200, so only the upload to Google Cloud Storage is failing.

Could you check the transcriber-eu bucket / WMR node for our tenant ?

Thanks a lot !

 

[Morgane]

Nothing is currently published on status.3cx.net, but a comparable platform-side transcription degradation was posted there on 20 Aug 2025.

One question that may shortcut the investigation: was any credential rotated or renewed around 2026-08-21 on the transcription path (service-account key used to sign the URLs, bucket IAM bindings, WMR node certificates)? A stale signing key alone would not explain the intermittency, but a partial rotation across the WMR fleet, or IAM propagation on the transcriber-eu bucket, would ?

 

[Morgane]

Sorry, I forgot to mention: this is a 3CX-HOSTED instance

 

[NikosT_3CX]

@Morgane as I can see your license key is 3CX AI.

The available options for transcription are Google, OpenAI, and Grok.

https://www.3cx.com/docs/voicemail-transcription/
https://www.3cx.com/docs/openai-transcription/
https://www.3cx.com/blog/releases/ai-transcription-grok/

Can you setup one of these and then check again ?

 

[Morgane]

Hello @NikosT_3CX
Thanks for your reply
I have switched to OpenAI to fix temporary the issue.

Our license is AI Edition (48SC). We only need voicemail transcription, not call recording transcription.

Your own announcement of 10 Feb 2026 states: "voicemail transcription remains available in the Enterprise/AI edition at no additional cost […] You can continue using the 3CX Transcription service for voicemails for free!"
https://www.3cx.com/blog/news/enterprise-plus-cloud-transcription/

This matches what we observe: it worked until 2026-08-21 10:00, unmetered (credit=0 on every successful callback), and then uploads started being rejected with HTTP 403.

Could you confirm whether this entitlement has been withdrawn — and if so, when it was announced?

 

[Morgane]

@NikosT_3CX "3CX Transcription Service (Cloud)" is still offered in our Admin Console > Integrations > Transcription, with our AI Edition 48SC license (expiring 12/03/2027). It is not greyed out or hidden

That matches your own documentation. https://www.3cx.com/docs/ai-transcription/ (last updated 5 May 2026), section "License Requirements": For Voicemail Transcription: Requires a 3CX AI Edition license, where voicemail transcription using 3CX AI is free. The setup it describes is exactly ours. Your first link, https://www.3cx.com/docs/openai-transcription/, says the same for any license of 8SC or higher.

So I don't understand why it stopped working :'(

A few points that argue against this being a license limitation:

• It worked on this instance until 2026-08-21 10:07 (+02:00), unmetered — credit=0 on every successful callback.
• It did not stop cleanly. On 21 Aug, 18 of 29 uploads failed with HTTP 403 while 11 succeeded, and 5 voicemails were transcribed normally that day. An entitlement removal would be binary, not 38% successful.
• The error is a bare HTTP 403 from storage.googleapis.com/transcriber-eu on the signed-URL PUT. All 75 control-plane calls to wmr.3cx.net returned 200, and there is no HTTP 587 / "Insufficient 3CX AI Credit" anywhere in the logs.
• The inbound callback works: when an upload succeeds on the first attempt, POST /webmeeting/finishedaiconversionarrives within ~3 s. So this is not the wmr-in.3cx.net / 34.40.92.110 firewall requirement either — and this is a 3CX-hosted instance anyway.
• AI Edition is the top edition and ENT+ no longer exists. If this feature is not available with our license, there is no license it would be available with ?

This looks like a backend issue on our tenant rather than a licensing one ?

We have switched to OpenAI to restore service as a temporary solution

Thanks for your help on this case !

 

[NikosT_3CX]

@Morgane you may find the below Blog Post which explains the License Edition Changes.
Check here :

https://www.3cx.com/blog/news/ai-edition/

3CX to Support Grok in Update 9​

In update 9, 3CX will support GROK for transcription. Grok transcription is significantly cheaper than Google, OpenAI and even 3CX cloud transcription.

Therefore, 3CX has decided to retire ENT+. As you may recall, ENT+ was made available to our partners and customers earlier this year. Since then, market conditions have shifted rapidly. Transcription services are now widely available at significantly lower cost, with providers such as Grok offering more competitive pricing than any other provider. As a result, 3CX will no longer actively promote this edition and will instead focus on supporting third-party providers.

 

[Morgane]

Hi @NikosT_3CX

so, if I understand correctly: going forward only third-party cloud providers (Google, OpenAI, Grok) will be supported for transcription, and the 3CX Cloud Transcription Service is being withdrawn — including for voicemail on the highest AI Edition license?

We've already moved to OpenAI to restore service in the meantime, but I need to clarify whether the 3CX Cloud Transcription Service is being removed, to tell my customer.

Thanks again !

 

[bitn2]

Hi @NikosT_3CX

so, if I understand correctly: going forward only third-party cloud providers (Google, OpenAI, Grok) will be supported for transcription, and the 3CX Cloud Transcription Service is being withdrawn — including for voicemail on the highest AI Edition license?

We've already moved to OpenAI to restore service in the meantime, but I need to clarify whether the 3CX Cloud Transcription Service is being removed, to tell my customer.

Thanks again !

Yes, only thirdparty cloud providers. 3cx Cloud isnt avaiable anymore.