It is an offence to sell, offer for sale, possess or transport for sale or exchange, any live bird unless it is a species listed, as a bird which may be sold, in part 1 of schedule 3 to the Wildlife and Countryside Act. To be legally sold the bird must be bred in captivity and be fitted with a closed leg ring.
The international commercial trade in certain species of wild caught birds also needs to comply with the Convention on International Trade in Endangered Species (CITES) to which the UK is party and which is implemented in the UK through the EU Wildlife Trade Regulations. This is a multilateral environment agreement which aims to ensure that trade in endangered species does not threaten their survival by controlling international trade in these specimens through a licensing system. CITES prohibits nearly all international trade in wild caught specimens of the most at risk species which are listed on Appendix I. Species that are not currently threatened with extinction but for which uncontrolled trade would not be sustainable, are included on CITES Appendix II and can only be traded internationally with the correct permits. These permits will only be granted if their trade is considered not to be detrimental to the survival of the species in the wild.