Clubs sometimes conclude deals at the last minute and it is not always easy for them to get everything completed and sent over by the deadline.
The deal sheet allows a club to confirm that a deal has been reached in order to allow for additional time to submit the remaining documentation.
For a deadline of 23:00, the deal sheet cannot be used before 21:00 and needs to arrive fully completed before the transfer window closes.
Once the sheet arrives, clubs have got another two hours, or until 01:00, in which to submit the full paperwork.
But if a club are looking to complete an international transfer, they still have to comply with the FIFA Transfer Matching System (TMS) deadline of midnight.
Example of deal sheet
Also in this series
Part 2: How do clubs begin 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?