The Home Office publishes statistics on firearm and shotgun certificates issued by police forces in England and Wales under the Firearms Act 1968. This provides a useful account of the number of firearms that are lawfully owned. The latest figures on the number of firearm and shotguns on issue are available from tables 1 and 3 of the ‘Firearm and Shotgun Certificates in England and Wales Statistics - Financial Year 2017/18’ publication.
Data as at 31 March 2019, will be reported in the ‘Firearm and Shotgun Certificates in England and Wales Statistics - Financial Year 2018/19’ publication. This has been pre-announced on gov.uk to be released in June/July 2019.
In relation to illegal firearms, the National Ballistics Intelligence Service (NABIS) and wider law enforcement regularly assess the volume of illegal firearms used in crime in the UK. NABIS produce quarterly reports on the threat, but their assessment is continuous and key information is shared amongst law enforcement on a real time basis. This information is operationally sensitive and not published.
Annual statistics on the number of firearm and shotgun certificates granted, renewed and revoked by police forces in Scotland are published by the Scottish Government. The figures are considered to be broadly comparable with those for England and Wales, due to the common legislation that governs the certification process.
The Police Service of Northern Ireland lists its statistical outputs on the Statistics page of its website, but there are no series that are directly compara-ble to those for England and Wales.