“Net 30” sounds simple: pay within 30 days. But in real operations, there’s a huge difference between Net 30 days (calendar days) and Net 30 business days (working days).
Try it by country: Spain, United States, Mexico, Brazil.
Why it matters
- Cash flow: a 2–3 week shift changes your forecast.
- Disputes: vendors and customers often assume different definitions.
- Compliance: some industries have strict “business day” rules.
Net 30 calendar days
This is the straightforward version: invoice date + 30 days. Weekends and holidays do not pause the countdown.
Net 30 business days
This version counts only working days. Weekends are excluded, and many organizations also exclude public holidays (depending on contract wording and jurisdiction).
A concrete example
Invoice date: April 1. If you count 30 calendar days, the due date is around May 1 (depending on month length).
If you count 30 business days, the due date is typically 6+ weeks later because you skip weekends — and potentially additional holidays.
How to avoid misunderstandings
- Write it explicitly: “30 calendar days” or “30 business days”.
- Define holidays: specify which country’s holiday calendar applies.
- Confirm the weekend rule: some industries treat Saturdays differently.
- Document the calculation method: attach an example in the contract if high value.
Best practice for international teams
If invoicing crosses borders, choose a single reference calendar and state it (for example, “business days in Spain, excluding Spain public holidays”). Otherwise, the same phrase can mean different due dates in different countries.
Conclusion
“Net 30” is not always “30 days”. If your contracts or workflows depend on working days, use a business-day calculator (and the right holiday calendar) to avoid surprises.