I've been trying to book for the last 24 hours a really good priced itinerary based on the SPOOKY savings deal (ends today). The problem I'm running into is that I'm receiving an error over and over that "Customer number '900991XXXXX' does not exist." (X replaced my actual numbers for security) when I attempt to move to the next step on the screen where you enter the passenger data for all the members of your party. Strange thing is that the customer number (aka frequent flyer number) is auto populated by Frontier because I'm logged into the website under my account. The auto populated number cannot be edited on the booking screen with passenger details as it's based on your logged in profile. I checked and confirmed that the customer number is indeed the accurate customer number for my account (at least the auto-populated # matches the frequent flyer # in my profile).

I've attempted to use different browser (IE and Chrome), tried clearing the cache on both browsers, and tried using two different laptops. Same error.

I want to book under my account as I'm 100K and want the benefits to apply to my entire family on the itinerary. So trying to book as my wife's account will not help.

I even attempted to book using the iPhone app, but at that same step in the booking process I'm receiving an error that "Failed to connect to the server and we're unable to continue. Any changes made will be lost".

I've sat for hours on the chat line, but no customer service person ever joins. I've sent messages directly on Facebook, as recommended on their website, but no one has even looked at it. I tried calling the phone number, but as soon as you select either website help or reservations, it just directs you back to the website.

I want these tickets as it's a great deal and the SPOOKY deals ends tonight.

Anyone else having this problem? Any suggestions?

I'm having the exact same issue. My wife was almost successful in a chat session to get the flight booked, but they wouldn't give us the "kids fly free" option since it wasn't being booked online; they seemed to have forgotten the entire purpose of our chat in the first place. I've had no luck reaching anyone on the chat and I've been on hold for the last 21 minutes (the message indicated that it could be as long as 2 hours). Not sure of any other options other than to forego the kids fly free (which is not really an option since that's the only reason we signed up for the den club and have already sunk $100).

It's clearly a backend technology issue. When I attempt to book the tickets via their iPhone app, I get the server error message at the same exact step in the booking process.

So frustrating. I don't want to lose out on these tickets. It's the best price I've seen in in the last two months.

As an update, I was able to reach an agent on the phone. I was trying to purchase "kids fly free" tickets, which are clearly an option on the Frontier website for the day of my flight (several flights that day did not have the option, but two flights did). The phone agent told me that the date I was flying (December 28) was a blackout date for kids fly free. He showed me the "terms and conditions" page on the website that did, indeed, list December 27-28 as blackout dates. Why they would then advertise December 28 as a "kids fly free" option is unknown to me. Regardless, he booked the flight for me (paying for kids) and waived the booking fee; he also gave me the discount den price for the tickets, which saved about $5/person/each way. I don't know if this is the problem that caused the error message, but once I discovered that the kids fly free wasn't an option I became uninterested in fixing the glitch and just wanted to be done.

For getting 100k benefits to other members on the itenary, try the following.. start without logging in, select regular fare (discount dden doesn’t work as it forces you log in), on the screen to enter passanger info, log in, it populates the first passanger info but will have an option to uncheck first passanger info to clear. Renter your frontier #, info (remembers bday!) and then other passanger info without frontier numbers. It will let you go to next screen with bundle package applied. I booked a trip with 4 of us yesterday with those steps.. good luck..

It seems like this problem only comes up if I book for myself and at least 1 other person. Booking for myself works fine.

Tried this method and I'm still receiving the following website error "ERROR Customer number '900991XXXXX' does not exist."

Just tried to revalidate.. these steps works for me.. make sure “passanger1 is the logged in member” checkbox is not checked.. this checkbox comes only when you start wth regular fare and then login in on passengers info entry screen.. manually enter 100k member number and info as passanger1.. don’t enter frontier number for other passengers..

Only worked for me if 100k member is entered as passenger 2. Did not work even if 100k member info manually entered as passenger 1.

Just an update.

I can successfully get through the booking process if I book a ticket just for myself. The error occurs when I attempt to add one or more additional passengers to the itinerary (which I kinda need to do since it is a family of four and I want us all to get the 100K benefit).

The fact I can book a ticket for myself with the auto-populated passenger data, including the FF#, leads me to conclude that the actual number itself is correct and the error is something wrong in their backend code.

So I tried another booking permutation to see if I can get it to work.

I logged in as my wife under her Frontier account so she would become passenger one. I then entered my data as passenger number two. I received the same exact error as before "Customer number '900995XXXXX' does not exist.". But this time the frequent flyer number the website says does not exist is my wife's. So the website is erroring for me on what ever FF# is entered as passenger number one during booking. Claims the number does not exists and stops the booking process, when the number clearly does exist.

I've been trying to book for five days (since 10/26) and continuously receive the same error. Five days and they still have not fixed it.

mine & some others' seemed to successfuly book online...
why won't ya chat or call in to see why yours has had issues with online booking; if all's still well, ask agent to book for ya this time, hoping ya next online attempts will go smoothly

BE AWARE when booking your ticket with online chat or phone, you will not be able to select The WORKS bundle if you're 100K elite.

And that's a huge difference, because you can no longer refund, change the flight

and THERE IS NO WAY the WORKS Bundle could be added later on.

I think the problem is that no one can be logged in. Everyone's Frontier number must be added manually. In your example, your wife cannot be logged in (and neither can you).

And be aware that the WORKS bundle must be actively selected when booking while not logged in. The WORKS bundle is selected automatically when logged in as 100K, so I almost missed the WORKS bundle selection because I assumed that the WORKS was automatically selected like before.