With the 2017 season here, stay up to date with the latest player signings, moves and speculation from all the counties.
Counties are allowed to field two overseas players in Twenty20 games, with up to four registered for that competition, although only two can be registered at any one time, and registrations must be for a minimum of 10 days.
Only one overseas player is permitted in the County Championship and One-Day Cup competitions.
Guide to abbreviations
Also shows, where relevant, players' previous counties
KPK: Kolpak contract
YTH: From youth teams
EUP: European Union passport
UKP: Born overseas, but has UK passport
Kolpak contracts are signed by foreign players, using a European Court ruling to avoid counting against the quota of one overseas player per club.
Players who moved counties or retired during the 2016 season are included on the 2016 list. Have we missed anyone? Please let us know.
Other news: The county have announced a new coaching set-up, with ex-captain Kim Barnett as director of cricket, supported by Twenty20 specialist coach John Wright, first XI support coach Steve Stubbings and development coach Mal Loye. AJ Harris has left his post as academy director, while seamer Tony Palladino has taken a player-coach role. Championship captain Billy Godleman will also lead the one-day side following Durston's departure, with new vice-captain Wilson skippering the T20 side.
Overseas player: Stephen Cook (South Africa, for first half of season); Tom Latham (New Zealand, for second half of season)
Possible signings: Hampshire are reportedly interested in Worcestershire all-rounder Moeen Ali, who will be out of contract at the end of the summer, though Warwickshire are favourites for his signature and Middlesex are also rumoured to be interested.
Other news: Hampshire were reprieved from relegation because of Durham's financial problems. Craig White has replaced Dale Benkenstein as head coach. Overseas signing Bailey will skipper the County Championship side once he arrives in May, with club captain James Vince still leading in limited-overs cricket.
Possible departures: England spinner James Tredwell has asked to speak to other counties because of a lack of playing time, while batsman Daniel Bell-Drummond has been linked with Warwickshire. Both are out of contract at the end of the season.
Possible signings: Middlesex are reportedly interested in Worcestershire all-rounder Moeen Ali, who will be out of contract at the end of the summer, though Warwickshire are favourites for his signature and Hampshire are also rumoured to be interested.
Overseas player: Kumar Sangakkara (Sri Lanka); Aaron Finch (Australia, primarily for Twenty20 but also as Championship cover while Sangakkara is at the Caribbean Premier League); Moises Henriques (Australia, for Twenty20 while Sangakkara is at the CPL)
Possible signings: Ex-Leicestershire batsman Angus Robson has joined on what the county describes as "a season-long trial" in which he will be registered to play for the 2nd XI and in the Sussex Premier League, as he looks to earn a full contract.
Possible signings: Worcestershire all-rounder Moeen Ali, who will be out of contract at the end of the summer, has been heavily linked with a return to Warwickshire, though Middlesex and Hampshire are also reportedly interested. Warwickshire have also been linked with a move for Kent batsman Daniel Bell-Drummond.
Possible departures: England all-rounder Moeen Ali, who has two seasons to run on his contract, which runs out at the end of the 2018 season, has been heavily linked with a return to Warwickshire, although Middlesex and Hampshire are also reportedly interested.