俺也改造好了一个tenant.

First month, late. I warned of the late fee.
Next month, late, plus paid only $1400 instead of the full amount of $1450. When I called him, he insisted he mailed $1500.

I sent a certified letter immediately.

Five days later, I claimed that I was in the court to sue him and requested him to mail me $50 additional rent plus $200 later fee immediately, or I would start the eviction process.

He did.

Never late since then.