Public-sector organisations are good customers. They have to be fair, honest and professional in the way they choose suppliers and in any dealings with them. Most are also long-standing, stable customers, and have to pay in good time and in line with agreed contract terms. Public-sector organisations have to pay within 30 days (or any other agreed period) of receiving a valid bill or invoice. You will find more information on this later in this guide. You may also find that trading successfully with the public sector can make your business a real option for private-sector customers. All public-sector organisations buying in goods and services must get the best value for money. This means.