Using the BitGo web wallet customers can grant users access to their wallet to enforce policies or enable multiple spenders. They can do so by defining various roles (Admins, Spenders, Viewers) to these users. To add users to a wallet, click on Add users > type email address, invite message and role.
Note: Currently, you can only add existing BitGo users to your wallet. If you would like to add someone who is a non-BitGo user. Ask them to sign up using this link: https://www.bitgo.com/wallet and then share the associated email address with you. Once, they confirm their email address and configure 2FA, you can add them to your wallet.