Follow these steps if you are already a member.
Log into GPP.
Select, sign up a new member.
Choose your referal code,
Select "family" in choose your membership.
Pay for all 3 with ebullion, keep a record of the transaction No.
Back on the GPP website you will note that you can now sign up 3 members.
Complete the first one, note that your referral (code) is correct.
Continue with the remaining 2, change referral (code) if you want all 3 in a straight line.
If you get booted for some reason, log back into GPP.
Select sign up a new member. Choose "family" as above.
On the payment page, click this --> (paid)
You will be asked to input the ebullion transaction No.
If all Ok, you can continue your sign up process.
Good luck
paddy