United Flight AC640 Deals & Information (2025/2026)

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United Flight 640 Route Deals From $244

The cheapest prices found with in the last 7 days for return flights were $176 and $244 for one-way flights to Denver Intl. for the period specified. Prices and availability are subject to change. Additional terms apply.

Tue, Oct 14 - Wed, Oct 15
YVR
Vancouver Intl.
DEN
Denver Intl.
$176 Roundtrip, found 21 hours ago
$176
Roundtrip
found 21 hours ago
Select United flight, departing Tue, Oct 14 from Vancouver Intl. to Denver Intl., returning Wed, Oct 15, priced at $176 found 21 hours ago
Tue, Oct 14 - Wed, Oct 15
YVR
Vancouver Intl.
DEN
Denver Intl.
$217 Roundtrip, found 21 hours ago
$217
Roundtrip
found 21 hours ago
Select United flight, departing Tue, Oct 14 from Vancouver Intl. to Denver Intl., returning Wed, Oct 15, priced at $217 found 21 hours ago
Tue, Oct 14 - Wed, Oct 15
YVR
Vancouver Intl.
DEN
Denver Intl.
$273 Roundtrip, found 21 hours ago
$273
Roundtrip
found 21 hours ago
Select United flight, departing Tue, Oct 14 from Vancouver Intl. to Denver Intl., returning Wed, Oct 15, priced at $273 found 21 hours ago

Frequently asked questions

What route does flight number UA640 take?
UA640 is used on multiple routes, but the most common is between McCarran Intl. Airport (LAS) and O'Hare Intl. Airport (ORD). If you're lucky enough to score a direct flight, you'll land in around 3 hours and 48 minutes. Multi-stop flights can also use the same number, as can services on other routes.
How often is UA640 on time?
The most popular route of United Airlines flight number UA640 flies between Las Vegas, NV Airport (LAS-McCarran Intl.) and O'Hare Intl. Airport (ORD) and runs on time 70% of the time. Still, it's good to allow a little buffer room if this is your flight number. In the event of a delay, there is an average wait time of 27 minutes. This trip has a 1.45-star rating.
What terminal does UA640 fly out of?
If you're leaving from LAS, you'll most likely board from Terminal 3. The most popular route for UA640 is McCarran Intl. Airport (LAS) to ORD, which is a direct flight.
What kind of plane is on flight number UA640?
It's possible you'll be heading off on a Boeing 737-900 if you've booked a ticket from McCarran Airport to O'Hare Intl. Airport (ORD), a common route for flight UA640.
If I am not able to travel due to COVID-19, can I change my flight to a later date?
For more info about changing your UA640 flight with Travelocity, please visit our Customer Service Portal.