Does the pattern give instructions for that? Sometimes they explain it toward the beginning of the pattern.
You can bind off at each end though. Bind off one stitch one you start the row and when you get down to the end bind off the previous stitch over the last stitch and turn. At least I think you can do that.
I've never knit a sweater flat only in the round. I know other members have so they can let you know for sure.