Hi Bob,
Unfortunately, the portal relies on the email address of the contact in Method when registering users in order to connect them with the correct customer information. Navigate to Customize > Portals and select Edit… on your portal. Based on the information on Step 1, you have a couple of options here.
1) Customize a screen so that you can register users yourself. This would simply require you to enter a username into the PortalUserName field and a password into the PortalPassword field into the correct record on the Contacts table. You can then provide this to your customer to allow them to sign in.
2) Use a custom field for the “Field containing Email” dropdown that you have populated with unique email addresses. This will allow the customer to register themselves, as there will be no duplicate emails.
Since you mentioned that most of your customers are setup with multiple jobs, it’s worth noting that each job is a separate customer record. The way the portal is setup by default, your customers will only see transaction details for the job or the parent which the contact is attached to and not all jobs. This can be altered by performing screen customization to the portal screens. You may want to consider reaching out to a Method partner or getting in touch with your account manager to have our professional services team do this for you.
I hope this helps.
-Audisho