Additional bank slots

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What are bank slots?
Every account has access to a bank which has a limited amount of space for storing items.

Increase your bank space
Bank Boosters +50 can be purchased from Solomon's General Store, these will permanently increase your maximum bank space by 50. 

You can purchase a maximum of ten Bank Boosters. Members can get four more Bank Boosters for free, accumulating to a total possible 700 extra bank slots. Free players may use the extra space obtained for free-to-play items only.

You can find more information on bank slots here.