Phrasal Verbs with PAY

pay back
to return money that you borrowed from somebody
I have to pay back my brother for that loan.

pay off
to produce a result that you want
I’m happy that all of our hard work has finally paid off.

pay off
to finish paying money owed for something
They paid off their mortgage after fifteen years.

pay out
to pay someone as a result of an insurance claim, investment, etc.
How long will the policy pay out?

pay up
to pay money that you owe
I had a hard time getting him to pay up.