With the January transfer window set to close the 20 Premier League clubs can look to bring in or ship out players before the deadline of 23:00 GMT, 31 January.
Premierleague.com looks at the mechanics of how a transfer deal is completed.
Part 1: What is the deal sheet in transfers?
Part 2: How does a club begin the process of completing a player transfer?
Part 3: What is the Premier League's role in the transfer process?
Part 4: What is FIFA's Transfer Matching System?
Part 5: How does the work-permit process work for transfers?
Part 6: Rules governing the third-party ownership of players
Part 7: Is a fax machine used for transfers?
Part 8: How many loans are allowed by Premier League clubs?