PHP Accounting and Transaction System (Buy/Open Source or Build?)

Question

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?

Answer 1

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.