Championship sides Bolton, Fulham and Nottingham Forest are under a transfer embargo for the rest of the season after breaching Football League rules in 2014-15.
Fulham and Forest both exceeded Financial Fair Play limits of permitted maximum losses of £6m for a season.
Bolton failed to submit their required accounts and are unable make transfers until they comply with FFP obligations.
Premier League Bournemouth face a fine after also exceeding the permitted sum.
The Cherries were promoted to the top flight after winning the Championship last season.
Millwall also exceeded the allowance but have not been punished after they were relegated to League One.
What the FFP embargo means
Clubs are not permitted to pay (or commit to pay) transfer fees or compensation fees for professional players.
Clubs can sign a goalkeeper on an emergency basis.
Clubs cannot pay a loan fee to another club, they may only pay the player's wage (or a contribution towards it).
For incoming players, clubs can only pay agents' fees as a benefit in kind to the player in question (as long as they do not exceed the £600,000 employee costs limit).
Clubs can register players under the age of 21 for non-first team matches.
Fulham and Forest will have the opportunity to have the embargoes lifted in June.
To do so, they will need to prove they have stayed within an operating loss of no more than £3m, with a maximum of £3m of shareholder investment for the 2015-16 season.
The ban for Forest is an extension on their current one, having been unable to sign players since December 2014 because of FFP restrictions placed on them.
Bolton, who have £172.9m of debt, said they were confident they would achieve FFP, but said they would be unable to sign and submit their accounts "until both the short and longer term funding issues the club are currently facing are resolved".
Meanwhile, the Football League said it is also in discussions with a number of other clubs over their FFP submissions, with any further embargoes "to be announced in due course".
One of those clubs is understood to be Premier League leaders Leicester.
Bournemouth said they were hopeful of a satisfactory outcome after confirming they were in discussions with the Football League about their sanction. Their fine has not been revealed.
QPR breached FFP rules in 2013-14 - the season they were promoted to the Premier League - and face a fine of up to £58m.
They announced their intent to challenge the legality of the Football League's FFP rules on 11 May, the day after they were relegated back to the Championship. That process is still ongoing.
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