Azure

Azure Resource Naming Scopes

Q: Which Azure resources require globally unique names?

Several Azure resources require globally unique names due to DNS constraints, including Storage Accounts, Key Vaults, App Services, Azure SQL Servers, Cosmos DB Accounts, Container Registries, Data Factories, Function Apps, Event Hub Namespaces, Service Bus Namespaces, Front Door, Traffic Manager Profiles, Redis Cache, HDInsight Clusters, and IoT Central Apps. These resources need globally unique names because they are publicly accessible via DNS and cannot have naming conflicts across the entire Azure platform.

Q: What is the difference between globally unique and resource group unique naming scopes?

Globally unique names must be unique across all Azure subscriptions and regions worldwide, making them harder to obtain but necessary for publicly accessible services. Resource group unique names only need to be unique within a specific resource group, allowing you to reuse the same name in different resource groups or subscriptions, which provides more flexibility for naming resources.

Q: What are the naming character restrictions for Storage Accounts and Key Vaults?

Storage Accounts allow only lowercase letters and numbers and must be 3-24 characters long. Key Vaults allow alphanumeric characters and hyphens and must also be 3-24 characters long. Both resources require globally unique names due to their DNS-based access patterns.

Q: How do Virtual Machines naming requirements differ between Windows and Linux?

Windows Virtual Machines have a maximum name length of 15 characters, while Linux Virtual Machines can have names up to 64 characters long. Both must be unique within their resource group and can contain alphanumeric characters and hyphens.

Q: Which Azure resources have region-specific uniqueness requirements?

Automation Accounts must be unique within both a resource group and region, Batch Accounts must be unique within a region, and Media Services Accounts must be unique within a region. These resources have region-level scoping rather than global or resource group scoping, which affects how you plan your naming strategy across multiple regions.

ARNAV SHARMA

2025.04.14 · 3 MIN READ

Azure azure DevOps

Last Updated on April 14, 2025 by Arnav Sharma

When deploying resources in Microsoft Azure, understanding naming conventions is essential for avoiding deployment errors and ensuring services function as expected. Different Azure resources have different naming scope requirements: some must be globally unique due to DNS constraints, while others only need to be unique within a resource group or subscription. In this post, I’ve compiled a comprehensive table outlining these uniqueness requirements so you can plan and name your Azure resources more effectively.

Here are some resources and their naming restrictions and requirements:

Resource Type	Uniqueness Scope	Naming Description / Limitations
Storage Account	Global	Globally unique DNS name. Lowercase letters and numbers only, 3-24 chars.
Key Vault	Global	Globally unique for secure DNS access. Alphanumeric and hyphens, 3-24 chars.
App Service (Web App)	Global	Globally unique domain. Alphanumeric and hyphens, 2-60 chars.
App Service Plan	Resource Group	Unique within resource group. Alphanumeric and hyphens, 1-40 chars.
Virtual Machine	Resource Group	Unique within resource group. Max 15 chars for Windows, 64 for Linux.
Virtual Network	Resource Group	Unique within resource group. Letters, numbers, periods, hyphens, 2-64 chars.
Subnet	Virtual Network	Unique within the VNet. Letters, numbers, periods, hyphens, 1-80 chars.
Network Interface	Resource Group	Unique within resource group. Letters, numbers, hyphens, 1-80 chars.
Public IP Address	Resource Group	Unique within resource group. Letters, numbers, hyphens, 1-80 chars.
Network Security Group	Resource Group	Unique within resource group. Letters, numbers, hyphens, 1-80 chars.
Azure SQL Server	Global	Globally unique DNS name. Lowercase letters and numbers, 1-63 chars.
Azure SQL Database	SQL Server	Unique within SQL server. Letters, numbers, hyphens, 1-128 chars.
Cosmos DB Account	Global	Globally unique DNS name. Lowercase letters and numbers, 3-50 chars.
Container Registry	Global	Globally unique login server. Lowercase letters and numbers, 5-50 chars.
Kubernetes Service (AKS)	Resource Group	Unique within resource group. Alphanumeric and hyphens, 1-63 chars.
Data Factory	Global	Globally unique. Alphanumeric and hyphens, 3-63 chars.
Synapse Workspace	Global	Globally unique URL. Letters, numbers, hyphens, 3-63 chars.
Logic App	Resource Group	Unique within resource group. Alphanumeric and hyphens, 1-80 chars.
Function App	Global	Globally unique domain. Letters, numbers, hyphens, 1-60 chars.
Event Hub Namespace	Global	Globally unique. Letters, numbers, hyphens, 6-50 chars.
Service Bus Namespace	Global	Globally unique. Letters, numbers, hyphens, 6-50 chars.
Application Gateway	Resource Group	Unique within resource group. Alphanumeric, hyphens, 1-80 chars.
Load Balancer	Resource Group	Unique within resource group. Alphanumeric, hyphens, 1-80 chars.
Front Door	Global	Globally unique. Letters, numbers, hyphens, 3-50 chars.
Traffic Manager Profile	Global	Globally unique DNS name. Letters, numbers, hyphens, 1-63 chars.
Redis Cache	Global	Globally unique DNS. Letters, numbers, hyphens, 1-63 chars.
Automation Account	Resource Group & Region	Unique in RG and region. Alphanumeric, hyphens, 6-50 chars.
Batch Account	Region	Unique in region. Lowercase letters and numbers, 3-24 chars.
Bot Service	Global	Globally unique. Alphanumeric, hyphens, periods, 2-64 chars.
Cognitive Services	Resource Group	Unique in RG. Alphanumeric, hyphens, 2-64 chars.
HDInsight Cluster	Global	Globally unique. Letters, numbers, hyphens, 3-59 chars.
IoT Central App	Global	Globally unique. Lowercase letters, numbers, hyphens, 2-63 chars.
Lab Services Plan	Resource Group	Unique in RG. Alphanumeric, hyphens, 1-100 chars.
ML Workspace	Resource Group	Unique in RG. Alphanumeric, hyphens, 3-33 chars.
User Assigned Managed Identity	Resource Group	Unique in RG. Alphanumeric, hyphens, 3-128 chars.
Maps Account	Resource Group	Unique in RG. Alphanumeric, hyphens, max 98 chars (incl. RG name).
Media Services Account	Region	Unique in region. Lowercase letters and numbers, 3-24 chars.
NetApp Files Account	Resource Group	Unique in RG. Alphanumeric, hyphens, 1-128 chars.
Notification Hubs Namespace	Global	Globally unique. Letters, numbers, hyphens, 6-50 chars.
Operational Insights Workspace	Resource Group	Unique in RG. Alphanumeric, hyphens, 4-63 chars.
Recovery Services Vault	Resource Group	Unique in RG. Letters, numbers, hyphens, 2-50 chars.
Resource Group	Subscription	Unique in subscription. Letters, numbers, (), ., _, -, 1-90 chars.
Role Assignment	Tenant	Globally unique GUID.
Role Definition	Tenant	Globally unique GUID.
Policy Definition	Subscription or MG	Unique within subscription or management group.

Arnav Sharma Microsoft MVPMCT

Microsoft Certified Trainer · Cloud · Cybersecurity · AI

I help organisations secure their cloud infrastructure and stay ahead of evolving cyber threats. Microsoft MVP and Certified Trainer, author of Mastering Azure Security, and founder of arnav.au — a platform for practical Cloud, Cybersecurity, DevOps and AI content.

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