Yes. You are welcome to set up your clients’ websites to back up to your UpdraftVault account and charge them whatever you like. After one-time authorisation using your updraftplus.com login, your updraftplus.com login details are never needed again and are not stored in the UpdraftVault settings on your clients’ websites (in its place is a unique token with no other usefulness).
Posted in: UpdraftGold, UpdraftPlus Vault