It's one of the reasons I stopped accepting lawyers and law firms as clients. Every other client would pay on time. Those in the law field would consistently slow-pay, I believe because they knew they wouldn't get sued over it.

"That overdue invoice? Oh, we never received it. Send it again." "Oh, Jenna in accounting must have it, but she's on vacation for two weeks." "Oh, that's in process." "Oh, we still haven't received it." "Oh, you have a signature on a certified mail delivery? It must be upstairs for approval." "Oh, we've already run all the checks for the month, it'll be in next month's batch."

I eventually went to a pre-paid hours, payable by credit card-only model. It was the only way to stay afloat. Plus it was delicious when someone would use up all their hours and give give some excuse.

"Oh, we really need this on the site today." "No problem. I can do that as soon as you buy more hours."

"Oh, we'll get that paid next week." "No problem, your website went offline an hour ago and will be back when you buy more hours next week." Poof! payment comes through three minutes later.