There is no notification hub resource in my subscription but billing support said there is nottification hub availability zones usage

Hi,

This has been reported in the past by another person. I believe it is a bug. What I suspect happens is when notification hub is deleted for some reason the add-on fee doesn't get removed.

Please make clear to the billing support engineer (in case they are not already aware) that Availability Zones is an Add-on fee to a Notification Hub. If they cannot demonstrate that an availability zone Enabled Notification Hub existed during the periods where the availability zone add-on fee was charged then you are due a refund.

In other words, the notification hub availability zone usage fee requires the presence of a notification hub.

Have you gone through the previous months usage details and checked to see if you were charged for any Notification Hubs? For example, you can start by going to Cost Analysis for your subscription and then at the top click on View -- CostByResource and filter on one prior month at a time. Look to see if you have any of Resource Type Notification Hub Namespace (it will be there even for Free tier).

For granular details, please navigate to Cost Management + Billing, on left click on Billing - Invoices blade. To the right of each invoice, click on Actions menu (three dots) and choose Prepare Azure usage file. It takes a moment to generate the file, and then you may download it and open it using Excel. Search in the file to see if you can find any Notification Hubs that exist (not just the availability zone fee).

Screenshot from Notification Hubs pricing page:

Please click Accept Answer and upvote if the above was helpful.

Thanks.

-TP