I’ve been doing some work with the Magento e-commerce platform lately and my task was to create a new payment method to use during the standard checkout process.
After much searching online, it seems that any available tutorials for custom payment methods either don’t work, are incomplete or worked in previous versions but are now updated. I developed this using version 1.3.2.2 of Magento.
I’m writing this tutorial with the intention of it being the definitive guide to creating a custom payment method.