Merriam-Webster - Definition of "Pay Off" (transitive verb) to pay (a debt or a creditor) in full
Merriam-Webster - Definition of "Pay Up" (transitive verb) to pay in full
According to the dictionary, both phrases could mean to pay in full. So, is there any difference between these two at all? Or they can be used interchangeably?
While you are correct that they both can be used to settle a debt, the difference is amount of coercion implied.
"Pay off" is used when you voluntarily settle the a debt, either all at once or over time:
After getting a larger bonus than expected, Dan decided to pay off the loan on his car.
Buying a home outright is usually too expensive, so most people choose to open a mortgage which allows them to pay off the home over a number of years.
"Pay up" meanwhile, suggests that someone is forcing you to settle the debt (all at once), often before you might be able to pay.
My client owed me a lot of money, but I had to take them to court to get them to pay up.
The loanshark cornered the hapless shopkeeper. "You have until Friday to pay up," he growled, "else I'm going to have to come back here with some buddies and not ask you so nicely."
Basically, "pay off" is polite, and "pay up" is not.
How would you like to pay off the balance on your account today?
Your account is overdue. If you don't pay up, we're going to have to take legal action.
These phrases have overlapping meanings and different nuance.
Both pay up and pay off can mean to clear a debt make a payment that is due. However, pay off is transitive, with either the debt or the creditor as object. On the other hand, pay up can be intransitive, and often is. When it is transitive, it's usually the amount of money that is the object, and you may then also get a prepositional phrase indicating who they are paying.
Pay up is also more likely to be used impolitely, or as part of an instruction or even threat.
Examples:
It's going to take me years to pay off my student loans.
I need to pay off that loan shark if I don't want my legs broken.
I can't believe there's still £2000 to pay off on my credit card.If you don't pay up, I'm going to break your legs.
Okay, we've eaten our meal, I guess we'd better pay up and leave.
My cars going to get repossessed if I don't pay up.
Pay off also has an additional sense, also used in the sense of paying someone, but not paying back a loan or settling credit. It's used for bribes and other corrupt payments, hush money, that sort of thing.
If you want to drive through that part of the country, you've got to be ready to pay off the guards at the checkpoints.
There was a woman with a story that would have sunk the campaign, but we paid her off. She'll keep quiet for now.
