The first month that you use your heavy vehicle during the tax period.
The current tax period, for which you’ll be filing your Form 2290, runs from July 1, 2021 to June 30, 2022.
So if you worked your heavy vehicle in July this year, that’ll be your first use month.
Can I pay the Heavy Vehicle Use Tax I owe with a credit card?
No, that would just be a little too easy, wouldn’t it?