: By default, clients attempt to renew their activation every 7 days . Successful contact resets the 180-day clock.
| Channel | Method | Suitable for | |---------|--------|---------------| | | Buy through Microsoft Volume Licensing Service Center (VLSC) | Businesses, non-profits, government | | Microsoft 365 Apps for Enterprise | Subscription with LTSC as alternative | Organizations needing cloud + local | | Retail (One-time purchase) | Available as Office Home & Business 2021 or Professional 2021 (not LTSC) | Individual users | | OEM | Pre-installed on new PCs | System builders, large resellers | Microsoft Office Ltsc Professional Plus 2021 Kms Activator