Establishes standards in regards to the tracking of gun purchases by financial institutions

HB 51, a proposed Missouri bill, prohibits financial institutions from requiring the use of a specific "firearms code" (5723) for gun retailers or discriminating against them in payment processing. It bans banks and credit unions from declining transactions, charging higher fees, or limiting services solely because a business sells firearms or ammunition. The bill directly affects Missouri gun retailers, their customers, and financial institutions processing payments for firearms-related transactions. Enforcement would be handled by the attorney general, with potential fines up to $10,000 per violation for continued noncompliance after a warning. The law aims to prevent financial institutions from using transaction codes to track or suppress lawful firearm commerce.