An internal market operates inside an organisation or set of organisations which have decoupled internal components. Each components trades its services and interfaces with the others. Often a set of government or government-funded set of organisations will operate an internal market. Services provided by an internal market are often but not always available on the Open market.

In the United Kingdom, the BBC under John Birt introduced an internal market amongst its different components - Technology, Production, News and so on.

In the EU, an internal market is said to operate between different countries and national governments.