The travel industry has come a long way from the early days of the airline GDS reservation system, and that’s particularly true with most hotel reservations. But sometimes hotel reservations seem to disappear in the cloud, so to speak.

I’ll never forget back in the 1980s booking a Marriott in Florida for a Sunday night on Friday afternoon through our SABRE computer and calling the hotel with a client’s special request. Not only did they not have the room confirmed, but also I found out that Marriott often didn’t send Friday reservations to hotels until Monday morning.

Fortunately, the client never heard that story. I got a room booked directly. Barely.

These days, many major hotel systems have a direct link into the GDS and many reservations are at the front desk almost instantly. “Many” being the operative word, instead of all. It doesn’t matter if 999 of a 1000 reservations get to the hotel with no problem, if you happen to be the 1000th.

So here are a few tips to help a front desk clerk find a missing reservation.

1. Have the confirmation number with you. This simple step can solve a lot of problems, if maybe there’s a misspelling, or the clerk typed in something wrong at checkin, or if the computer ran a name together in a weird way.

2. It’s good to have the confirmation number in the exact format sent to you by the agency or online booking tool or service used for the reservation. Since many of us (including me) transpose numbers when we are typing or writing fast, an original confirmation avoids such mistakes.

3. Have the number of the booking service, agency, hotel reservations service etc, handy. Even if the reservation is somehow lost, a travel agent can often call a help desk that will trace down the problem and get the hotel to honor the booking; ditto a central reservations office for a hotel chain or group.

Just as background, some hotels, like the Intercontinental Hotel Group, have all bookings in a central computer, others use reservations services. Any time a reservation message must be transferred from one computer to another, something can go wrong.

Plus, any time humans get involved in the process there can be more complications. Clients have had problems because a reservations agent interpreted two similar names as a duplicate reservation. Some travelers calling the hotel directly, accidentally cancel the wrong reservation. (This last happens a lot when common names and/or non-English speakers are involved.)

Even if the clerk says “never mind,” they have a room anyway, it’s worth a bit of effort to find the original reservation. From a travel agent point of view that saves an agency commission. From a traveler’s point of view, there is a good chance the reservation is in the hotel system somewhere, and he may end up with a room charge AND a no-show charge for the same night. (It is not only is it possible, it happens all the time.)

In any case, most lost reservations can be found with a bit of digging. In the long run, the easiest time to try to find them is at check-in, not after giving up and having to try another hotel.