United Airlines now allows you to pre-pay the fee for up to five checked bags when checking in online within 24 hours of your flight. By paying online at united.com through Jan. 31, you'll also save $3 on the fee for your first checked bag. With the discount, you'll wind up paying $12 instead of the usual $15. This discount applies through New Year's Day.
In an email to frequent fliers this morning, United also said, "We have also canceled our previously-announced plans to increase the domestic second bag fee from $25 to $50 one way. The fee to check a second bag on a domestic flight will remain $25 one way."
Third and fourth bags currently cost $125 per bag each way. Checking a fifth bag will set you back $250. For a chart of excess baggage fees, go to United's site.
Online check-in closes one hour before domestic flights and two hours before international flights.