I sat on that clause for almost a year before I added it.
Not because I didn't know how. Adding a line to an invoice template takes five minutes. I sat on it because I kept picturing the conversation where I'd actually have to bring it up, and every version of that conversation in my head ended with a client quietly deciding I wasn't worth the hassle anymore.
The client who finally pushed me over the edge was a marketing agency I'd worked with for almost two years. Good work, decent rates, the kind of relationship you don't want to mess with. Except twice in six months, my invoice slid to 45 days. Not because they couldn't pay. Their accounting person told me, almost cheerfully, that they "batch vendor payments at the end of the month, sometimes the next month." I was a vendor. I was also apparently optional.
So I added a late fee. 1.5% per month on anything past 30 days, spelled out right on the invoice template, nothing hidden in fine print nobody reads. I didn't send an announcement or a policy update email. I just changed the invoice and figured whoever noticed would notice.
The agency never said a word. Their payments got faster, actually, which felt like proof the delay had never been about cash flow in the first place. It was about priority. I'd been at the bottom of a list, and a late fee moved me up it without anyone having to admit that's what happened.
