Greenfinches are found from the Canary Islands, Madeira and northwest Africa, through all of Europe except the far north and into central Asia. They have been introduced into the Azores, New Zealand, southeast Australia and Argentina. Originally found mostly in bushy areas and forest edges, since 1950 they have become increasingly common in built-up areas. They are  sedentary apart from some east to west movement, within the country and from the near continent, in autumn, reversing in spring.
    In Britain their numbers had remained fairly steady with only minor fluctuations since the 1960s up until the mid-1980s when they began twenty years of sustained growth. Then in 2005 they were hit by an outbreak of trichomonosis, a disease transmitted by the parasite Trichomonas gallinae, which affects the upper digestive system making it difficult for the affected bird to eat. This led to a precipitate decline in numbers - in the ten years between 2008 and 2018 the summer population of Greenfinches in the UK declined by 68%.
    In Wiltshire they have been regarded as extremely common at least since the mid-19th century, except that they are absent from most of Salisbury Plain and other areas of higher ground, and only patchily common in a few other places. The county has not been spared the effects of trichomonosis, though it appears not to have been as damaging as in some other counties: Birds of Wiltshire recorded them in 824 tetrads, with breeding in 578; WTA2 recorded them in 807 tetrads with breeding in 436.

The following references are used throughout these species accounts, in the abbreviated form given in quotation marks:
1968-72 Breeding Atlas” – Sharrack, J.T.R. 1976:  The Atlas of Breeding Birds in Britain and Ireland. T. & A. Poyser
“1981-84 Winter Atlas” – Lack, P.C. 1986:  The Atlas of Wintering Birds in Britain and Ireland. T. & A. Poyser
1988-91 Breeding Atlas” – Gibbons, D.W., Reid, J.B. & Chapman, R.A. 1993: The New Atlas of Breeding Birds in Britain and Ireland 1988-91. T. & A. Poyser
Birds of Wiltshire” – Ferguson-Lees, I.J. et al. 2007 : Birds of Wiltshire, published by the tetrad atlas group of the Wiltshire Ornithological Society after mapping fieldwork 1995-2000. Wiltshire Ornithological Society.
Bird Atlas 2007-2011” – Balmer, D.E., Gillings, S., Caffrey, B.J., Swann, R.L., Downie, I.S. and Fuller, R.J. 2013: Bird Atlas 2007-2011: the Breeding and Wintering Birds of Britain and Ireland
WTA2” – ("Wiltshire Tetrad Atlas 2 ") the present electronic publication, bringing together the Wiltshire data from “Birds of Wiltshire” and “Bird Atlas 2007-11”, together with data from further fieldwork carried out in 2011 and 2012.
"Hobby" - the annual bird report of the Wiltshire Ornithological Society.