Associate Bank

Everyone wants to belong, even banks. An associate bank is a bank that belongs to some larger organization. Think of it like a club, as if your bank joined a bowling league or the Benevolent and Protective Order of Elks
In the case of a bank, these associations tend not to be of the social or fraternal types, however. It's more likely to be something like a credit card network, like a bank that issues a Visa or Mastercard.