When Lefteris Michailidis didn't get a confirmation e-mail from Priceline ( for a recent three-night hotel stay in London, he thought his bid wasn't accepted.

"I assumed that there was no transaction and I booked a hotel with Hotwire instead," he says.

He assumed wrong.

"A few days later, I received an e-mail from Priceline saying that I should get ready for the trip to London," he recalls. "I was confused and I called Priceline to find out that they had charged me for a hotel room, although I thought that the transaction I originally tried to make with them did not go through because I never received a confirmation e-mail."

As it turns out, Priceline had charged him for his room after all. Now he would pay for two sets of hotel rooms during his visit. (Priceline's "name-your-own-price" rooms are completely nonrefundable and can't be changed.)

Michailidis' experience raises a question that comes up often in my consumer advocacy practice: When is a confirmation confirmed? Is it when you press the "enter" button on your PC? When you get an e-mail with a confirmation number? Or is it when you actually board the plane, open the door to your hotel room, or turn the ignition on your rental car?

In 99 out of 100 cases, an e-mail with a confirmation number is reason enough to believe you have an actual reservation. But Michailidis was that 1% where the e-mail -- or more precisely, the lack of an email -- wasn't enough.

"E-mail as a means of confirming a reservation isn't always reliable," Priceline spokesman Brian Ek told me. "That's why we recommend checking the website or calling."

(Take a minute to let that sink in. Here's Priceline, an online travel agency, saying e-mail can be unreliable.)

Michailidis didn't think it was fair to pay for a hotel twice, so he disputed the charge with his American Express card. But Amex sided with Priceline.

"The merchant has advised that the customer has the option of visiting the 'Check Your Request' section of the website or by calling 1-800-Priceline to check the status of an accepted offer," it said, by way of explanation. "The merchant sends a courtesy e-mail to the customer to visit the 'Check Your Request' section of the website, however, e-mail is not always reliable and the customer should not rely on it as method of determining the status of their offer."

In other words, don't count on an e-mail from Priceline.

I asked Priceline to take another look at Michailidis' complaint. I mean, if you never send a customer an e-mail, then expecting him to pay seems a little unreasonable, doesn't it?

Priceline's response: But we did tell him.

"The bid was accepted at 2:51 a.m. on 5/31, which means the confirmation would have been available online at that time," Ek told me by e-mail. "An e-mail was sent at 2:52 a.m. on the 31st to the e-mail address provided. Someone did go online to view the reservation details at 12:16 p.m. on the 31st."


So when is a confirmation a confirmation? I'm leaning toward, "don't believe it until you see it," but obviously, that's a worst-case scenario -- one exacerbated by the fact that Priceline's model is slightly different than the rest of the travel industry, in that its products have lots of unusual restrictions.

Still, here are a few words of advice: The next time you make an online reservation, be sure to whitelist the domain of the travel company you're dealing with. (So, for example, if you're booking through Orbitz, you'll want to add "" to your e-mail whitelist, so all of its e-mails will get to you.)

Also, check your credit card statement regularly, and certainly no more than 24 hours after you've made a purchase. You should be monitoring your credit card purchases anyway.

And if you have any doubts about your reservation, call your online travel agency -- and assume nothing.

Christopher Elliott is the author of "Scammed: How to Save Your Money and Find Better Service in a World of Schemes, Swindles, and Shady Deals" (Wiley). He's also the ombudsman for National Geographic Traveler magazine and the co-founder of the Consumer Travel Alliance, a nonprofit organization that advocates for travelers. Read more tips on his blog, or e-mail him at Christopher Elliott receives a great deal of reader mail, and though he answers them as quickly as possible, your story may not be published for several months because of a backlog of cases.)