noun
usage-based billing; metered billing; pay-as-you-go
A billing system where charges are based on actual usage or consumption, common for utilities, cloud services, and mobile data plans.
このクラウドサービスは従量制で、使った分だけ料金がかかります。
This cloud service is usage-based; you pay only for what you use.
電気料金は従
Electricity rates are metered, so if you conserve energy, your bill goes down.
Compound of 従量 (じゅうりょう, 'according to quantity') and 制 (せい, 'system').