I have developed a WordPress plugin that saves a form submission to a database , then redirects to Tranzila iframe.
I had fully integrated Tranzila with a handshake security future and a payment notification future.
Then I have created an MS Access database and came up with  a way to sync new payments to it using XML.

it was a special billing system for that allows to same company to bill this client again at a later date  using credit card tokens.

I think it can be an excellent solution for many types of businesses like country clubs or classes because it does payments without maxing out the credit card’s credit limit. in country clubs or classes cases the annual payment can be large.  so it is a good solution for clients.

Integrating with Captain-Forms was a little challenge, Captain-Forms is a closed-source system that runs on a 3rd-parity server with a very limited integration ability. the customer service told me there was no option to do what I wanted, to do the integration it required some “skilled guess-work and investigation”-(hacking maybe) to accomplish that, and I did it successfully.

The customer was very happy he could accomplish payments successfully without big changes. without replacing the beautiful Captain Forms.