Which Economy are You Getting?
When doing a fare search on United.com or speak to an agent you need to make sure what classification your fare is in before you book it. United has a couple of economy fares that have very big differences in them. So if you are speaking to an agent and you tell them you want an economy seat let them know if you are wanting Basic Economy or Standard Economy. Depending on whether the search is filtered to exclude or include Basic Economy, the lowest fare that comes up may be Basic Economy and you end up purchasing the wrong ticket. So be very clear on which economy ticket you are purchasing.
Basic economy which will be the lowest possible fare. However there are a lot of restrictions on this fare. For example, you will not be able to choose your seat ahead of time. Your party will not necessarily be seated together, you will be put in whatever seats are leftover from those who chose a fare where they can choose their seats. So your party may be spread out throughout the plane. You will not be able to use the overhead bins. The only carry-on you will be able to bring is one that fits under the seat.