When are free calls used in a month when you are on a paid plan?

My current quota is for 2 million calls that is about to run out (3% left) with my subscription expiring on May 7. At this point, it’s become clear I will need around 2.5m calls a month.

Will my free 500k calls be used once my paid quota has finished? Based on my usage numbers per day, I believe so, but it’s unclear.

If I was to downgrade to 1m or re-subscribe to a 2m package, it says it will start after the current one expires, potentially resulting in downtime for a few days... unless my 500k calls will be used in the interim. I know if I was to upgrade to the 5m package, it will begin immediately, ensuring no downtime, but it will be unnecessary 1) if it was going to fallback to 500k free calls which is more than enough to cover usage for the few days before a new sub package begins and 2) because I don’t need 5m calls in a month.

Hope someone can help! I’ve contacted Apple but not heard anything so far. Thanks so much.

When are free calls used in a month when you are on a paid plan?
 
 
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