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
UseThe carrier incurred a $500 fine for an overweight load. (one penalty, taken on at once)
UseDetention pay accrues by the hour after the first two hours. (builds up over time)
AvoidThe 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.