To form a SMSF you need 2 x trustees unless it is a company SMSF then only 1 trustee is fine.
Once the SMSF is set up, anyone can be a member and there is no limit to the amount of members.
The accounts are calculated on what each member contributes and works on a pro rat rate of return.
eg if all the assets in the fund returns 10% in a year and member A holds 75% of the fund, then member A will get 75% of the return and the other member will get 25% of the return.
