Payable on receipt or within thirty days
Unless stated otherwise, an invoice is due on receipt. In practice, most businesses use a thirty-day term, sometimes longer in large organisations. The term shown on the invoice applies if it has been accepted, which is why it is useful to mention it in the quote or contract as well.
A short term can be justified for small amounts and private customers. For business engagements, a realistic term that is respected is better than a tight deadline that is routinely missed.