Firstly - I'm not an SFDC guy... so forgive me if I don't quite get the terms correct...

I'm working on requirements for integration and authentication across multiple systems, with the goal being that "Customers" and "Partners" will have access to our portal, which in turn links through to other systems like ServiceNow, Salesforce, etc. We are looking to do this using their 'email address' as their login ID in all systems.

Here's a scenario: Customer X logins into our portal and wants to request an additional service, clicking that link should either take them to ServiceNow (where no sales transaction is occurring) or potentially SFDC-CPQ (not sure yet if we plan to have customers 'self-generate quotes'). We want all that to happen without multiple login prompts.

Everything seems to be coming together except for SFDC as it seems user IDs need to be 'globally unique'. So I believe that means, if [email protected] is already using SFDC in their own organisation, we can not set them up as a user in our SFDC as [email protected] already exists as an SFDC user.

So the question - is that true for 'community users' too or is it handled differently? Surely many resellers are SFDC users internally, and also access their vendors SFDC systems and they don't have separate user ID / logins for each one??

Don't want to reinvent the wheel... so does anyone have a wheel out there for me look at?

Many thanks!

  • In my experience of Sites with user logins enabled, the username only has to be unique to that Site because all the URLs have an extra level of naming included (the Site prefix). But best wait for someone using communities (that I think layer on top of Sites) to confirm that (or not).
    – Keith C
    May 9, 2016 at 22:28

3 Answers 3


I can confirm that communities username should be unique across only that org and you can have two orgs with same username for community user license.


Assuming you want no additional login prompts = Single Sign On, then you can use a federation Id for the same user across multiple salesforce orgs -- just not one fed Id for multiple users in same org. Sorry to paste link but am on mobile -- fed id doc. Hopefully this points you in the right direction.


I think that for time of asking, and previous questions, this was true. However, in Winter 19, there was a new feature released https://help.salesforce.com/s/articleView?id=sf.networks_partner_username_uniqueness.htm&type=5

This relates to Partner community users.

Text from the feature:

You’re no longer required to create a username that is different from all previously created usernames, when adding someone to an Experience Cloud site. Select Require unique usernames for partners in this org to contain the unique username requirement to one org and one org only. After you enable this preference, it can’t be reversed

So what you need to do, is contact SF to enable this for your org.

  • By default Community external users' usernames only need be unique to the org. This is still the case. I frequently create external users on different orgs that share the same username (by that I mean every few days) without ever having to have such a feature enabled. I think this feature is specific to Partner users. I recommend you update your answer accordingly to highlight this point.
    – Phil W
    Jul 4, 2022 at 12:42
  • thank you, both the question and my answer relate to community users. I will make this more noticable. Also, this is default only to orgs created after Winter 19.
    – Saariko
    Jul 4, 2022 at 12:49
  • Like I said, customer community users still do not require globally unique usernames; this seems specific to partner community users.
    – Phil W
    Jul 4, 2022 at 13:03

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