TL;DR
WooCommerce Subscriptions only supports billing intervals 1–6 for days, weeks, months, and years. If you need intervals like 8 weeks, 10 months, 12 months, or 18 months, you can add them with a small PHP snippet. Once added, these new intervals automatically show up in the Buy Once or Subscribe for WooCommerce Subscriptions plugin as well. Just paste the code below into your functions.php or a custom plugin and you’re ready to go.
If you’re running a WooCommerce store with subscriptions, you’ve probably noticed that WooCommerce Subscriptions only lets you choose billing intervals between 1 and 6. That works for many stores, but what if you want to offer a subscription every 8 weeks, every 10 months, or even every 18 months?
The good news is that you can extend the billing intervals with a small code snippet, and once you do, those new intervals automatically appear in our Buy Once or Subscribe for WooCommerce Subscriptions plugin as well.
In this article, we’ll walk you through everything you need to know.
What billing intervals come standard in WooCommerce Subscriptions
By default, WooCommerce Subscriptions allows you to set recurring billing intervals in a “standard” range:
- You can choose a billing period of daily, weekly, monthly or yearly.
- For each period, the “interval” (i.e. how many units of that period) is limited between 1 and 6 — e.g. every 1 day, every 2 days, … up to every 6 days; or every 1 week, every 2 weeks … up to every 6 weeks; or every 1 month up to every 6 months; or 1 to 6 years.
- Once you pick a billing period and interval, the next payment date is calculated based on that. For example, if you select “every 2 months” and a customer signs up on February 15, the next payment will be on April 15.
Because Buy Once or Subscribe relies on the billing interval options provided by WooCommerce Subscriptions, the available subscription-frequencies in your plugin correspond to exactly that set.
Why You Might Want Longer Billing Intervals
- Seasonal or less-frequent deliveries
Maybe you ship products every 8 weeks, or you have a quarterly box that doesn’t fit neatly into the “every 3 months” model. Or maybe your product cycle is 10 weeks, 12 weeks, or something unique to your business.
With custom intervals, you can match your subscription schedule to your actual operation.
- Long-term memberships or service plans
Some businesses want billing cycles such as:
- Every 10 months
- Every 18 months or
- Every 2+ years
These cannot be created using the built-in options. Extending intervals opens up an entirely new way to structure your subscriptions.
How to add extra billing intervals in WooCommerce Suscriptions
If you want to enable intervals like 8, 10, 12, 18, or 24, you can do this by adding a simple snippet to your site. Add this code to your child theme’s functions.php file or in a code snippet plugin:
function eg_extend_subscription_period_intervals( $intervals ) {
$intervals[7] = sprintf( __( 'every %s', 'my-text-domain' ), WC_Subscriptions::append_numeral_suffix( 7 ) );
$intervals[8] = sprintf( __( 'every %s', 'my-text-domain' ), WC_Subscriptions::append_numeral_suffix( 8 ) );
return $intervals;
}
add_filter( 'woocommerce_subscription_period_interval_strings', 'eg_extend_subscription_period_intervals' );What this snippet does
- Adds 7 and 8 as additional intervals
- Works for all billing periods (day/week/month/year)
- Automatically shows these options inside WooCommerce Subscriptions
How this works with Buy Once or Subscribe for WooCommerce Subscriptions
Because Buy Once or Subscribe imports the subscription intervals directly from WooCommerce Subscriptions, any custom intervals you add via code (as shown above) will automatically become available in the Interval dropdown for each subscription plan.
Take control of your subscription strategy. Upgrade your store with Buy Once or Subscribe and unlock more recurring sales with zero friction.