The Lite plan is perpetual for 30,000 NLU items and one custom model per calendar month. Once you reach the 30,000 NLU items limit in a calendar month, your NLU instance will be suspended and reactivated on the first day of next calendar month. Lite Plan instances and the custom model deployed for those instances are terminated after 30 days of inactivity. We recommend the Lite Plan for POC's and the standard plan for higher usage production purposes.