The Personal Bank Upgrade allows you to open the Bank from the SkyBlock Menu from anywhere on skyblock. This upgrade is unlocked with Emerald VI.
Talking to the Banker in the Hub World resets the cooldown.
Upgrading it while the cooldown is active will shorten the cooldown to the new duration.
The Personal Bank can also be accessed with the personal bank item.
The name may be a bit misleading. If you are in a coop with someone, the personal bank will not keep your money for you. It is a portable way to access the bank.
This upgrade can be further upgraded by talking to