| Version 1.3.1 2021/03/17 | Check for PDT item_number, then item_number0, item_number_0, item_number1, item_number_1. |
| Version 1.3.0 2016/03/30 | Support Buy Now buttons with up to three Option dropdowns or text fields. |
| Version 1.2.0 2015/10/23 | Grouping of parameters. Improved debug information in html comments. Allow custom paypal.com site specification for testing. Workaround for transactions missing gross payment. |
| Version 1.1.1 2015/09/20 | Minor update of tags for organizing Stacks. |
| Version 1.1.0 2015/05/05 | Convert transaction id to uppercase before confirming with PayPal. Consider the Item ID (item_number in URL) as case insensitive. |
| Version 1.0.0 2015/01/12 | Initial release of PayPalStack stack. |