Billing for subscriptions with a monthly interval depends on the day of the month the subscription was created. If the subscription was created on or before the 28th of the month, it gets billed on the same day, every month, for the duration of the plan. Subscriptions created on or between the 29th - 31st, will get billed on the 28th of every subsequent month, for the duration of the plan
You can also pass invoice_limit, which lets you set how many times a customer can be charged on this plan. So if you set invoice_limit: 5 on a monthly plan, then the customer will be charged every month, for 5 months. If you don't pass invoice_limit, we'll continue to charge the customer until the plan is cancelled.
Now that we have a plan, we can move on to the next step: subscribing a customer to that plan. There are a couple of ways we can go about creating a new subscription.
You can create a subscription for a customer using the initialize transactionAPI endpoint, by adding the plan_code of a plan you've created to the body of your request. This will override the transaction amount passed, and charge the customer the amount of the plan instead.
Once the customer pays, they'll automatically be subscribed to the plan, and will be billed according to the interval (and invoice limit) set on the plan.