Payment Processing Alliance PPA is the premier provider of check21, remote deposit, ACH and merchant credit card solutions to various industries. The offering of PPA includes a full lockbox scanning system as well as an advanced medical banking offering. Ownership of PPA seen the need for a secure third party payment provider that was safe, reliable and forward thinkiing. There are many third party payment providers and only one provider of choice, PPA. PPA is the provider of choice for lockbox, remote deposit and custom deposit processing applications. The needs of all clients are at the forefront and the ownership of PPA takes every step to guard all relationships.