I'm trying to integrate an accounting solution into a web app I am developing. I need to be able to post recurring transactions, one time transactions, invoice people, etc.
Do most sites do this custom in-house or integrate with some type of accounting system API. I know basically everyone needs to use a merchant account to process credit cards, but what about storing the accounting data to know when and how much to bill?
Buy the accounting package (or use an open source one, if available), then integrate with it. That's what I do. It would be nigh impossible for a one man show to build an accounting package that gives the finance and book-keeping folks everything they need and maintains compliance with GAAP and applicable laws and does it more cheaply than purchasing an off-the-shelf accounting system with an API or import/export functionality.