Credit card payment gateway in PHP? [closed]
Stripe has a PHP library to accept credit cards without needing a merchant account: https://github.com/stripe/stripe-php
Check out the documentation and FAQ, and feel free to drop by our chatroom if you have more questions.
If you need something quick and dirty, you can just use PayPal's "Buy" buttons and drop them on your pages. These will take people off-site to PayPal where they can pay with a PayPal account or a credit card. This is free and super easy to implement.
If you want something a bit nicer where people pay on-site with their credit card, then you would want to look into one of those 3rd part payment providers. None of them (that I'm aware of) are completely free. All will have a per-transaction fee, and most will have a monthly fee as well.
Personally I've worked with Authorize.NET and PayPal Website Payments Pro. Both have great APIs and sample code that you can hook into via PHP easily enough.
There are more than a few gateways out there, but I am not aware of a reliable gateway that is free. Most gateways like PayPal will provide you APIs that will allow you to process credit cards, as well as do things like void, charge, or refund.
The other thing you need to worry about is the coming of PCI compliance which basically says if you are not compliant, you (or the company you work for) will be liable by your Merchant Bank and/or Card Vendor for not being compliant by July of 2010. This will impose large fines on you and possibly revoke the ability for you to process credit cards.
All that being said companies like PayPal have a PHP SDK:
https://cms.paypal.com/us/cgi-bin/?cmd=_render-content&content_ID=developer/library_download_sdks
Authorize.Net:
http://developer.authorize.net/samplecode/
Those are two of the more popular ones for the United States.
For PCI Info see: