Microsoft Advertising Introduces Dual-ID Account Linking for Better Security
In August 2026, Microsoft Advertising introduced mandatory dual identification (Dual-ID) when linking advertising accounts to manager accounts. The change affects agencies, large advertisers, and companies managing multiple accounts.
The new system is intended to reduce the risk of accidentally or fraudulently linking accounts belonging to someone else.
How Account Linking Worked Before
Microsoft Advertising allows advertisers to link advertising accounts to Manager Accounts so agencies can centrally manage clients' campaigns, budgets, and access permissions.
Previously, one identifier was enough to send a linking request: either the advertising account number or the manager account number.
An agency received the number from its client, sent an access request, and the account owner approved the link.
However, using only one identifier increased the risk of sending requests to the wrong owner or attempting unauthorized account linking.
What Changed
Now, when creating a new link, Microsoft Advertising requires two identifiers to be provided together.
The combination depends on the type of link:
- Manager Account Linking (CID): Manager Account Number + Manager Account ID.
- Advertising Account Linking (XID): Manager Account Number + Account Number.
The first option is used to link manager accounts to each other; the second is used to link an individual advertising account.
As a result, an account number alone is no longer sufficient to create a new link.
The change became generally available by the end of August 2026.
How to Set Up Account Linking
In Microsoft Advertising, open Tools → All accounts → Accounts Summary → Requests → Link to accounts.
Select the link type, enter the required identifiers, and complete the linking settings, including access permissions.
After the request is submitted, the account owner must approve it. The new system does not provide automatic access without the client's approval.
Account Number and the internal Account ID are different identifiers. They should not be confused when completing the form.
What This Means for Agencies and Developers
The change applies only to new linking requests. Advertising accounts that are already linked continue to work without renewed approval.
For agencies, the update adds an additional identifier verification step when onboarding new clients.
Microsoft separately notes that advertisers using the platform's web interface do not need to make technical integration changes.
When using custom API tools, developers need to account for the requirements of the relevant link-management methods and check the current documentation.
Dual-ID does not affect advertising algorithms, bidding strategies, CPA, or ROAS. It is an update to security and access management.