My first invoice had no payment terms at all. It said the amount, my bank details, and nothing about when payment was due. The client paid after 47 days. I remember checking the account every morning for a week and a half, wondering whether asking about it would seem pushy.
That was the year I learned that payment terms are not paperwork. They are pricing. Here is the math I wish someone had walked me through before I sent that first invoice.
Net 30 means you are the bank
Net 30 reads like a neutral deadline: pay within 30 days. Look at it from the other side of the table. Your client has received the work. You have received a promise. For those 30 days, you have issued an interest-free loan to a company that is probably larger than you.
Big companies know this perfectly well. Corporate finance teams track days sales outstanding the way engineers track latency, and stretching it is free money for them. A procurement department that pushes a small vendor from Net 30 to Net 60 has effectively borrowed from that vendor at zero percent, and it shows up as an efficiency win in their annual report.
