Kraken Futures

It is currently only possible to create sub-accounts on Kraken Futures.

Kraken.com

Sub-accounts are not supported on the main Kraken.com platform.

It is possible to create multiple accounts, however, they cannot be linked together; their sign-in information, balances, trading volume, fee discounts and verifications will be separate. 

It is also not possible to transfer balances, trading volume, fee discounts or verification status to another account.

For business accounts, you may designate multiple account accessors to your account. However, the accessors would still need to share the same account sign-in information for a business account.