# Software Management Services Subscriptions (The explanation on this page is for programmers to learn about subscriptions and licenses, and is not intended as an in-depth description of the subscription options and pricing. If you are interested in using the Software Management Service API and want to learn about pricing, please contact your organization’s Verizon Wireless account representative. If you do not have an account representative or are not sure who your representative is, please reach out to us at iotdeveloper@verizon.com.) ThingSpace Software Management Service is available in two types of subscriptions: - Monthly Recurring Charge (MRC) (one year minimum) for a specific number of licenses that allow unlimited upgrades on each licensed device. Example: A customer could choose an MRC based service for 10,000 licenses. - Event-based billing, or billing after using the service for one-time upgrades. Here the customer subscribes to the service up front but the billing is initiated after completion of firmware upgrades. The purchase/subscription is at the account level. When a customer subscribes to the service, all the qualified devices in the account become eligible for the service. The license can be assigned any time prior to scheduling an upgrade. Licenses are assigned at a device level. - For event based billing, the customer can use the Software Management Service for any of the eligible devices in the account. Once a license has been assigned to a device, and a firmware/software upgrade has completed, the license cannot be used again. - For an MRC subscription, the customer must assign licenses to individual devices before a firmware/software upgrade. Once a license has been assigned to a device and a firmware/software upgrade has completed, the license cannot be removed from that device. Once a license is applied to a device, you can schedule campaign firmware/software upgrades regardless of the protocol used. Use the [v3 Assign license API](/docs/premium-apis/software-management/software-management-v1/api-endpoints/software-management-licenses-v1/assignlicensestodevices) to assign licenses regardless of v1, v2 or v3 API is used to schedule. For example, if a device uses LWM2M for baseband FOTA and the same device uses HTTP for application FOTA, only one license is needed for the device to be able to use any or both services.