What is the PAYG Subscription Model?

Q: What is the PAYG (Pay-as-you-Go) subscription model in Zyxel Nebula?

A:
The PAYG (Pay-as-you-Go) subscription model is a flexible license management option available in Circle, Zyxel’s subscription and license management platform. It allows organizations to enable selected Nebula services and pay through monthly billing, instead of purchasing fixed-term licenses

How PAYG Works

When an organization upgrades to PAYG:

• The Nebula Professional Pack is automatically included for any device that supports cloud-managed mode.

• Optional packs such as the Gold Security Pack (GSP) can be added for supported firewalls (USG FLEX, ATP, H-Series).

• After activation, devices no longer show a fixed expiration date. Instead, subscription costs are calculated each month.

Billing Method

• Unit of billing: PAYG charges are calculated by device-day (DD) — the number of days each device is assigned to the PAYG organization’s inventory during the billing period.

• Billing cycle: Invoices are generated on the 1st or 2nd day of each month (depending on time zone).

• Device management: Devices can be added, removed, or transferred at any time. The cost automatically adjusts based on the active days.

• Special cases:

  • Devices with bundled/add-on licenses continue to use them until expiry.

  • Firewalls in monitor mode do not generate PAYG charges.

Cost Calculation and Rounding

• The monthly cost is based on the ratio of total device-days to a full 31-day month, multiplied by the standard monthly rate.

• Costs are always rounded up to the nearest full month. For example, if the usage equals 1.13 months, the bill will be calculated as 2 months.

• This ensures billing consistency, but may mean higher charges if devices are frequently added/removed mid-cycle.

Grace Period and Overdue Payments

If a payment fails (e.g., expired or cancelled credit card), the PAYG organization enters an overdue status.

• A 15-day grace period applies:

  • During this period, services remain active.

  • Email reminders are sent to the organization owner every 3 days.

• After 15 days, the organization is downgraded to BASE status (or GSP disabled), and services are deactivated.

• Reactivating requires:

  • Settling the unpaid invoice.

  • Paying for the charges accumulated during the grace period.

Advantages of PAYG

• Flexibility – pay only for the devices and services actively used.

• Scalability – easily add or remove devices without worrying about license expiration.

• Simplified management – PAYG organizations in Circle are clearly marked with a blue “PRO” label, making license tracking straightforward.

• MSP-friendly – billing is centralized, which is ideal for managed service providers handling multiple customers.