Your account balance is made up of all posted credit and debit transactions. It’s the amount you have in the account before any pending charges are added. 

Your available balance is the amount you can use for purchases or withdrawals. It's made up of the account balance minus pending debit card authorizations and holds on funds. Items not reflected in your available balance include, but aren't limited to:

• Pay-at-the pump transactions or restaurant tips that aren't included in the original authorization.
• Checks written that haven't been cashed.
• Authorized automatic withdrawals, like your monthly gym membership or car payment. 
• Future payments scheduled through bill pay. 
• Authorizations that no longer appear as pending due to merchant delay. 
• Funds held from deposits.