"SubscriptionExceededMaxDomainLimit" while attempting to create an additional App Service Domain

Question

"SubscriptionExceededMaxDomainLimit" while attempting to create an additional App Service Domain

Koteru Reddy (LTIMindtree Limited) 85 Microsoft External Staff

We are encountering the error "SubscriptionExceededMaxDomainLimit" while attempting to create an additional App Service Domain in our 3P subscription. There does not appear to be any self-service or quota-based option to increase the App Service Domain limit from the Azure Portal.

Subscription ID: xxxxec86-xxxx-4b0c-xxxx-38771228xxxx

Aditya N 2,990 Reputation points Microsoft External Staff Moderator

2026-01-09T05:53:23.8533333+00:00

Hello @Koteru Reddy (LTIMindtree Limited)

Thanks for reaching out Microsoft Q&A.

We've provided the process for Microsoft employees in private message, please follow the same. Please let us know in case of any assistance.
Aditya N 2,990 Reputation points Microsoft External Staff Moderator

2026-01-14T07:01:17.39+00:00

Hello @Koteru Reddy (LTIMindtree Limited)

Please provide the information as requested over private message.
Shree Hima Bindu Maganti 7,580 Reputation points Microsoft External Staff Moderator

2026-01-14T17:11:56.62+00:00

Hello @Koteru Reddy (LTIMindtree Limited)
The SubscriptionExceededMaxDomainLimit error happens when an Azure subscription reaches the maximum number of allowed App Service Domains. This is a hard limit set by the platform, and there is no self-service or support option to increase this quota for any subscription type, including 3P subscriptions. This is intentional in Azure App Service. When this limit is reached, you should reuse an existing Azure DNS zone, such as arc-validation-conformance.com, to host additional services by adding the necessary A, CNAME, or TXT records instead of creating or buying a new domain. Azure DNS does not allow mapping or merging multiple name server sets for the same domain; each DNS zone can only be delegated to one name server set at a time. For isolation, use subdomains (e.g., apps.arc-validation-conformance.com) or migrate records into the existing DNS zone. Microsoft documentation confirms that App Service Domain limits cannot be increased and that a single Azure DNS zone can manage multiple services and subdomains.
https://learn.microsoft.com/en-us/azure/app-service/manage-custom-dns-buy-domain#limitations
https://learn.microsoft.com/en-us/azure/dns/dns-overview
https://learn.microsoft.com/en-us/azure/dns/dns-domain-delegation
Let me know if you have any further assistances needed.
Koteru Reddy (LTIMindtree Limited) 85 Reputation points Microsoft External Staff

2026-01-20T07:42:35.56+00:00

Hi @Shree Hima Bindu Maganti

As per discussions I have shared the observations in the private messages, could you please help me with that? Thanks!