Trouble adding a user for go payments credit card scanner. Added them in manage users, invitation sent but they cannot login. in create Intuit act says user ID taken

Hi there, kirst10mulligan,

Let me clear things out about adding a new user to your QuickBooks Payments account. QuickBooks Online (QBO) lets you add users to help manage your account.

However, for GoPayments, it should be done through the Merchant Service Center, not inside QBO. To do this, the following steps listed below will guide you through adding a user:

1. Sign in to Merchant Service Center.
2. Go to Account, then click Users.
3. In QuickLinks, select How do I add a new user?
4. Select the invite link.
5. Enter the email of the user you want to invite, then select a role.
6. They’ll receive an invitation email to start using QuickBooks Payments.

When it's already taken, that means they have an existing Intuit account. In their email, they can use the account by clicking the link under the USER ID column. The sample screenshot below will show them how the content looks like in the email.

You can find those steps above through this article: Add users to QuickBooks Payments  for more details.

Let me know if you have follow-up questions, and I'm always around to help you out.