I'll have to settle up what I owe for the phone.

我得付清所欠的电话费。

《柯林斯英汉双解大词典》

Our father had thousands of dollars of debt and owed people favors, many of who looked at us to settle up.

父亲背了好几千美元的债务，还欠下不少人情，很多人都指望我们能帮他了结。

youdao

When it's time to settle up, you won't get a bill: your waiter tells you the total and then you tell them how much you want to pay, including your "tip, " and hand over the money.

结账的时候，你不会收到账单：服务员会告诉你总额，然后你来告诉他们你想付多少，包括小费，然后把钱给他。

youdao

The cattlemen finally had to settle land of their own, putting up fences and cutting the size of their herds.

VOA: special.2010.03.18

In pre-1971 days, nations had to settle up on their trade balances.

FORBES: Occupy Wall Streeters Should Be Livid About Losing The Gold Standard

What's worse, there's no playbook for how to settle up.

FORBES: Magazine Article

In effect, Americans never have to settle up.

FORBES: Debts Must Be Reckoned With To Spark U.S. Renaissance