What does the subscription status of Cancelling mean?

When a customer is unsubscribed from a plan they will still have an amount of time remaining on the current renewal period, during which the subscription status will appear as Cancelling.

Once their current renewal period ends, the subscription status will update to Cancelled.

Example

1. A customer subscribes to a monthly recurring plan on June 17. The subscription status becomes Active.
2. On September 13 they unsubscribe from the plan. The subscription status updates to Cancelling.
3. On September 18 the subscription status updates to Cancelled.