If there is a central clearinghouse, the marketplace would be aware every moment in time which player had a debit or credit balance.

FORBES: Briefing Book: A. Michael Lipper

Since Square Wallet is linked to a debit or credit card, there is never a need to reload a balance.

FORBES: Starbucks Now Accepting Payments With Square Wallet

Square Wallet is linked to their debit or credit card, so there is never a need to reload a balance.

ENGADGET: Starbucks begins offering Square Wallet purchases from today

If you just need basic checking, bill pay, ATM access and a debit card, search for accounts that don't charge fees if you're below a minimum balance or fees of 25 cents or more for each check written.

FORBES: Banking