A mutual credit system owned by the users could charge zero interest with only a monthly service charge for keeping the records.

All of the people are seen as the owners, the paid professional administration is paid from a fund inspired by the writings of Silvio Gesell. I.E. everybody pays a little for a smooth running system of mutual credit.

Reputation records kept on participants.

Specie coinage recognized as a form of savings and used in a performance bond role.

Poor reputation; post a large performance bond.
Good reputation; low performance bond.

Any community could acquire a commercial banking license and operate the bank for the benefit and profit to the local population. Look to the example of the bank of North Dakota as pointed out by Dr Ellen Brown.