The concept

The Merchant ID, or MID, is the number that identifies your operation within the acquirer. The entire history hangs off it: volume, approval, disputes, and complaints.

It's the MID that gets monitored, and it's the MID that gets closed when the indicators go past the limit. That's why opening another account after a block rarely works: the link between document, domain, and product usually rebuilds the connection to the previous MID.

How it shows up in practice

Your infoproduct operation starts well, sales grow, but after a few months the acquirer terminates the account without much warning. You open a new account on another platform, changing your document or domain, hoping nobody discovers it's the same operation. The truth is the transaction history, chargebacks and complaints are all linked not just to the old MID, but to your product and the address you use.

We see our customers as invited guests to a party, and we are the hosts. It is our job every day to make every important aspect of the customer experience a little bit better.

Jeff Bezos Source: Jeff Bezos's letters to Amazon shareholders.

Any new MID will bring with it the reputation of the old one if the operation remains the same. That's why instead of trying to start over, the path is to fix what caused the termination: understand why the chargeback rate went up and solve it before opening a new account anywhere.