EZ pass

Once I accidentally went through the York maine EZ pass fast lane by mistake and I never got a bill in the mail as I don’t have an EX pass transponder. That’s a $4 toll at York. Another time recently I pulled up to a toll both in Portland Maine and there was no one there so I kept driving and I never got a bill in the mail. This never happens in New Hampshire. Has anyone had that experience in Maine, they don’t send bill out or something?