Switching Hotel PMS Software: What to Migrate, and What to Leave Behind

Most of the anxiety around switching property management systems is about data: what if reservations disappear, what if a guest's history gets lost, what if the new system shows up empty on day one. That's a real risk, but it's the easier half of the problem. Industry guides on PMS migration consistently point to the same actual failure point — not the data export, but the week you cut your OTA channels over from the old system to the new one. Here's what needs to move, what doesn't, and where to put your attention.

What actually has to move before cutover day

Not everything in your current PMS needs to travel to the new one. A few categories do, because operating without them on day one either loses revenue or breaks compliance:

Based on migration-checklist guidance from Smart Order, WebRezPro and HotelFriend (see Sources below) — treat these as practical starting points, not a guarantee specific to your contract or jurisdiction.

What you can safely leave behind

The instinct is to import everything "just in case." That's how migrations turn into multi-week projects. A few categories are better left in the old system, or exported as a static file instead of imported live:

• Historical reservations and old revenue reports. Keep roughly the last 12 months as a static CSV/Excel export for reference and reconciliation, rather than importing them as live records the new system has to reconcile against. You're very unlikely to need to check someone in from a stay that already happened.
• Stale marketing lists. If you haven't used a guest segment for marketing in over a year, it's not worth the data-cleaning effort to bring it along.
• Legacy report formats and dashboards. Rebuild the three or four reports you actually read every week in the new system rather than trying to replicate every report the old one generated.
• Point-of-sale, spa and activity history beyond what you need for reconciliation. These usually need their own disconnection/reconnection plan with the new PMS regardless, so don't bundle their historical data into the core migration.

One practical habit that shows up across migration guides: keep the old system's login active and the data accessible for a few months after cutover, purely for reference, rather than deleting the account the day you go live.

The part that actually breaks switches: the OTA cutover

The highest-risk window in any PMS switch isn't the data import — it's the few days where your channel manager has to start pushing availability and rates from the new system instead of the old one. Your new PMS almost certainly uses different internal room type IDs and rate plan codes than your old one, so the mapping to each OTA has to be rebuilt from scratch, and until it's tested, availability on that channel is unreliable. If two systems both believe they're the one controlling a channel's availability at the same time, the result is a double booking — and that costs you a guest, not just an admin headache.

What migration guides converge on to manage this:

• Cut channels over one at a time, not all simultaneously, so a mapping error on one OTA doesn't take down availability everywhere at once.
• Test with a dummy availability change before trusting the new connection — close out a room on the new system and confirm it disappears on Booking.com/Expedia within minutes, not hours.
• Confirm every future reservation exists correctly in the new system — right room type, dates and rate — before you let the old system stop controlling that channel.

Whether you run both systems in parallel for a short overlap or do one decisive cutover is a judgment call — guides differ, and the tradeoff is duplicate manual work (parallel) against a harder, cleaner break (decisive). Either way, the OTA mapping work is where to spend your caution, not the spreadsheet export.

Timing the switch

• Pick a lower-occupancy window for go-live day, not your busiest week of the year — you want room to fix mistakes without a full house watching.
• Give OTAs and other connected vendors notice — roughly two weeks is the recurring recommendation — so channel-side mapping and support are ready for your cutover date, not scrambling on the day.
• Check your current contract's notice period before you set a date. Some PMS contracts require 30–90 days' written notice to cancel, which can end up dictating your timeline more than the migration itself does.

A short practical checklist

• Export future/in-house reservations, flag prepayments separately.
• Export guest profiles with consent records intact.
• Pull open folios and financial data for your records.
• Document room types, rate plans and corporate rates as master data for the new system.
• Archive the last ~12 months of reservations/reports as a static file, don't import them live.
• Rebuild OTA/channel mappings one channel at a time, and test each with a dummy change.
• Set a low-occupancy go-live date, and give OTAs ~2 weeks' notice.
• Check your old PMS contract's cancellation notice period before committing to a date.

If you're earlier in the decision and haven't picked a new PMS yet, see How to Choose a Hotel PMS: 10 Questions to Ask and How Much Does a Hotel PMS Really Cost? first.