Fare dropped after I booked. Can I cancel and rebook at the lower price?

Depends on your fare and timing, but here is what to check:

1. The 24-hour window. For flights to or from the US booked at least 7 days before departure, you can generally cancel within 24 hours for a full refund, then rebook at the lower fare.
2. Free change or credit rules. Some airlines give you the fare difference as a credit if you change your flight, though many fares don’t allow it.
3. Check fees first. A change or cancellation fee can cancel out any saving.
4. Look at the new fare’s rules. The cheaper fare may be more restricted.

Compare the total cost before you click cancel. This how to cancel a flight booking guide explains the steps.