What's the difference between a PMS and a channel manager?

These two systems get confused frequently because they both touch reservations. The distinction matters because choosing one to substitute for the other creates real problems. What the PMS does: Stores and manages reservations from all sources. Tracks guest profiles, preferences, and history. Manages folios (charges and payments per stay). Coordinates housekeeping status across rooms. Runs night audit (the daily reconciliation process). Generates operational reports. Handles staff users, permissions, and audit trails. Often integrates with payment processing, accounting, and channel manager. The PMS is the operational backbone. Every guest interaction at the property runs through it. Examples: Cloudbeds, Mews, Apaleo, Little Hotelier. What the channel manager does: Syncs available inventory across all OTAs and the hotel's own booking engine. Pushes rate changes to all channels simultaneously. Manages OTA-specific restrictions (length-of-stay, closed-to-arrival, etc.). Pulls reservations from OTAs back into the PMS. Handles modifications and cancellations from OTAs. Reports channel performance. Often integrates with metasearch (Google Hotel Ads) and direct booking engines. The channel manager is the distribution interface. Without it, every OTA needs to be updated manually, and overbookings happen within weeks. Why people get them confused: Some products bundle both. Cloudbeds is a PMS that includes a built-in channel manager. SiteMinder is primarily a channel manager that includes a basic PMS option. Little Hotelier (a SiteMinder product) bundles both. The bundling creates the illusion that they are one product. Both touch reservations. From a hotel front-desk perspective, "the reservation came in" - they may not see whether it came through the channel manager from Booking.com or directly into the PMS. Both report on revenue. Both produce reports that look like they could replace each other, but they don't. When to use bundled (single vendor for both): small hotels under 30 rooms with simple distribution (3-4 channels) and straightforward operations. The bundled simplicity outweighs the depth limitations. When to use separate (best-of-breed): hotels above 30 rooms, hotels with 5+ active OTA channels, hotels with complex rate plans, hotels that want a specific PMS but it doesn't have the channel manager features they need. The integration between them matters most. Whether bundled or separate, the data must flow accurately and quickly: PMS reservations must update inventory in the channel manager immediately; OTA reservations from the channel manager must appear in the PMS within seconds with all guest data intact.