Net 30 is a form of trade credit which specifies that the net amount (the total outstanding on the invoice) is expected to be payment received in full 30 days after the goods are dispatched by the seller, or 30 days after the service is completed. Net 30 terms are often coupled with a credit for early payment; e.g. the notation "2% 10, net 30" indicates that a 2% discount can be taken by the buyer only if payment is received in full within 10 days of the dispatch of the goods, and that full payment is expected within 30 days. For example, if "$1000 2/10 net 30" is written on a bill, the buyer can take a 2% discount ($1000 x .02 = $20) and make a payment of $980 within 10 days.
Additional meaning of Net 30:
Net 30 is a term that most business and municipalities (federal, state and local) use in the United States. Legally speaking Net 30 means that buyer will pay seller in full on or before the 30th calendar day (including weekends and holidays) of when the Goods were dispatched by the Seller or the Services were fully provided. Transit time is included when counting the days, i.e. a purchase in transit for 7 days before receipt has just 23 additional days until payment is due to the seller. Net 30 payment terms typically have an interest penalty for not meeting these terms and they begin accruing on the 31st day after dispatch.