Virtual network peering is for virtual networks that belong to subscriptions in different Azure Active Directory tenants. Virtual network peering enables direct VM-to-VM connectivity across virtual machines deployed in different virtual networks.
In this post lets see how to enable vnet peering across different tenants, First you need to provide access to the other tenant as a guest users
A user from one tenant must exist as a guest user in the other tenant.
RBAC permissions: Network admin on the VNETs

Accept the invite


After you accept you should see the directory appearing as below.

Next you need to add the VNET Peering on both sides of the vnets for that you need to know the resource ID’s
- Resource ID can be found from VNET Properties

In the remote virtual network, please select resource manager and enter the resource ID of the other Vnet.

Select the directory and click on authenticate, This would check if the ID is having necessary permission on the VNET.
Same has to be repeated on the other VNET.


Now both the VNETS across different tenants are peered.