You’ll get the TER instruction manual. Scroll down to some information for providers. Click on that and you’ll see how to white list.

Look at the top of the page and click "Reviews". Then look immediately below where it said Reviews and click "More Searches". Scroll down to "Search Whitelist", click that. Enter your clients board handle ( or his e-mail address which will work if he gave you the one he has on his TER member account) and click search. His whitelist will come up and you click "Submit Referral".

...though from there it probably could figured out.