Can I share access to my account?

Yes, If you wish to share access to your account, You can invite him with desired permissions to your account. Please note: This feature is available for Premium, Premium+ and Enterprise plans. Compare plans here.   

Sendinblue account owners can delegate access to their account to multiple additional users.

Whether you are a marketing agency managing multiple clients, an enterprise with small/large teams, or a business owner requiring separate access for developers working on integration, you can collaborate with your team by inviting them to access your account without sharing your account credentials.

Invited users will not be able to edit your plan selection, manage access for other users, or see your billing and payment information.

Good to know:
1. If your account is under Premium, Premium+ or Enterprise plan, you can add up to two (2) additional users to your account at no extra cost. If you need more users please contact your account manager.
2. All additional users can access everything except account management details, like user access, billing, and payment information.
3: You can revoke/change the permission of the user at any moment.

Further reading