accrue / incur
Accrue, to build up by increments over time; incur, to bring a cost, liability, or penalty on oneself.
Accrue describes growth over time, and it is neutral: interest accrues on savings and on debt, and vacation days and late fees both accrue. Incur describes the act of taking something on through one’s own action, usually a cost, liability, risk, or penalty. You incur a debt when you borrow; interest then accrues on it. Do not use accrue for a single cost or penalty taken on at once.
Examples
Use The carrier incurred a $500 fine for an overweight load. (one penalty, taken on at once)
Use Detention pay accrues by the hour after the first two hours. (builds up over time)
Avoid The carrier accrued a $500 fine for an overweight load.
In accounting, an accrued expense is a cost incurred but not yet paid. That technical sense is standard on financial statements.