Recurring billing with Rails and ActiveMerchant: Best practices, pitfalls, gotchas?
We are prepping for the release of a large web application that has been in development for the past year. We are about to start the process of integrating ActiveMerchant to handle recurring subscription fees for the service.
I am looking for any advice regarding best practices considering our requirements (listed below) and any additional heads-up for common pitfalls or specific issues I should be giving special consideration. The payment gateway we will be using is PaymentExpress as it's one of the few supported gateways that has recurring billing and doesn't have any special conditions for companies operating outside of the USA. The business behind this application is based out of the UK.
Users of the application create an account with a sub-domain where they can access and customise the application and their data. Below are some of the requirements/features that might have an effect on how billing works:
- All users get a 30 day trial
- There are different plans, including a free one
- Higher priced plans have larger limits on the amount of data (e.g. users, projects, etc) they can have in their account
- Billing period will be monthly, beginning after trial
- There will be discounts/coupon codes to get a percentage off the normal price for a year on plans, etc.
- Plan pricing will change as features are added
Specific hurdles I can foresee will be things including the following:
- How to handle downgrading when they violate the plan limits for lower level plans.
- Behaviour when credit cards expire or payments don't go through (a read-only mode enforced, perhaps)
- When plan pricing changes, we want to honour previous prices for existing users for a time period (such as 6 months), then start charging higher rates. If the plan price decreases, it will take effect immediately.
Other advice that would be helpful would be anything regarding flow of the application. How should billing forms be presented to the user? When should credit card information be required? How should invoices be sent, stored, and accessible?
I should disclose that we plan to base a lot of the code base off SaaSy. SaaSy is designed to be used as a separate Rails app that handles all the signup and account management side of things. However, this doesn't work for us since we never planned for this from the beginning and it would be a tedious process to adapt our application to work like that. Consequently, we'll be pulling code and ideas from SaaSy and merging them into our app, a considerably less tedious task.
Answer
One thing I wanted to add: keep in mind you don't need to use the recurring billing feature that is built into the gateway. In general these systems are legacy and very difficult to deal with, we get spoiled in the rails world.
You get a lot more flexibility just using them for one purpose (to bill a credit card, and perhaps also store credit cards for PCI compliance). Then roll your own recurring billing in your rails app with a cron job, a date field for when they are paid through, and amount each person is paying (in case they used a coupon) etc.
One small example: sometimes people will cancel a monthly subscription in the middle of the month. They want to make sure they don't forget to cancel before the next payment. Most gateway recurring billing that I've seen will instantly terminate the account (or send you a message indicating this). In reality, the user has paid through the end of the month and should be given 2 more weeks of access. You can do this if you have rolled your own recurring billing in rails, but not if you are using the gateway recurring billing. Just a small example.