You should use two tables linked by your client Id serial number. In your clients table you have one record for each client and no duplicates. In your related services table, you have as many records as you need to list the client's services and they will take their client id number from the clients table so this gives you what you want, a unique client ID but multiple services listed.
You can use a portato the services table on your clients layout to see and edit their services.
The Client ID table should be renamed Clients and it should have an auto-entered serial number field added to it called client ID. That field and only that field should then link to client ID in Pass. Once that's done, you can double click the line linking these two boxes and select "Allow creation of Records via this relationship" for Pass. Finally, define a portal to Pass on your Clients layout. With that option selected, you can add a new Pass record for a given client simply by entering data in the bottom blank row of this portal.
I'm not sure this is what I need anyway - what I need is:
eg. If a client is entered multiple times in the database, they are assigned one coorspoding client ID number.
John Smith who I helped on 2/22/09
and John Smith who I helped again on 8/25/10
both display an id of "client 67" since they are the same person.
Any help would be greatly appreciated.
That all looks good. Does it work? (Portal, is something you can look up in FileMaker help to learn more.)