You can go to SIM authorizations to add managers for a specific SIM card.

Do you want to give someone else access to your SIM card?
- Log into your own account and add the e-mailaddress of the person you want to give access to your SIM card via your SIM authorizations.
- Next, have that person log into their account. They'll see a yellow notification on the website to accept access to a new SIM card.
- From that point on, they'll be able to top up that SIM card and check its usage.

Do you want access to someone else's SIM card? 
- Have the person whose SIM you want to manage log into their own account. Via their SIM authorizations they can fill in your e-mailaddress.
- Next, Log into your own account.They'll see a yellow notification on the website to accept access to a new SIM card.
- From that point on, you'll be able to top up that SIM card and check its usage.