January transfer window 2023: When does it open and close?
Premier League clubs can start making signings again from 1 January when the transfer window opens.
Clubs in Scotland, the English Football League and most of Europe's major leagues can sign players from 1 January, with some other windows opening the next day.
Some teams in the various UK leagues have already lined up signings to go through when the window opens.
However, clubs may have to wait a few days to play their new signings.
Usually players have to be registered with the Premier League by 12:00 on the working day before a game - so because of weekends and public holidays, it may be 4 January before anyone could make their debut.
Premier League clubs spent £295m on signings last January, the second-highest in history. 
record spend by English top-flight teams for a whole season has already been broken - even before this window starts - with £1.9bn shelled out in the summer.
English window closes at 23:00 BST on Tuesday, 31 January.
Nottingham Forest have signed Palmeiras attacking midfielder Gustavo Scarpa, 28, on a free transfer - starting on 1 January. That is their 23rd signing of the season.
West Ham have signed another Brazilian, 20-year-old Sao Paolo defender Luizao for an undisclosed fee.
Meanwhile, Newcastle have agreed a deal to sign 18-year-old Garang Kuol from Central Coast Mariners.
Celtic have already agreed two deals - Canada and Montreal right-back Alistair Johnston and Vissel Kobe defender Yuki Kobayashi.
Watford will sign Johnston's team-mate for club and country, midfielder Ismael Kone, and Fluminense youngster Matheus Martins.
Bradford, Blackpool, Fleetwood, Millwall and Oxford will sign League of Ireland players when the window opens too. 
Portugal forward Cristiano Ronaldo needs a new club and can join one once the window opens after his exit from Manchester United in December.
United, meanwhile, are keen to sign a replacement for the former Real Madrid player.