This “30 day” thing is so misleading. When does the clock start? When your billing clerk hits the print button on their computer? When you drop it into the nearest Canada Post mailbox? When you see it being scanned to your customer? Realistically the clock can’t start until you know for sure that your customer has it in their hands. Nobody, not even the worlds best payer, will start their payment process until they have the invoice. That is why you will see the words “upon receipt of invoice” included on almost everyone’s payment terms. Once your invoice has been received it is perfect acceptable to start the clock and expect to see payment on or about 30 days later, keeping in mind that virtually no one (especially large companies) issues payable cheques on a daily basis. In my opinion, if some says they will pay in 45 days, or even 60 days and they do exactly that, they are a more reputable customer than the one who claims to pay in 30 days and then lies to you as they stretch it out to 60+.