And while Portsnouth have been slow to get off the mark in January, a host of their rivals have wasted no time in adding to their ranks with some eye-catching deals.
Scroll down and click through the pages to see EVERY deal done in League One this month:
21. Sunderland AFC
In: Kyle Lafferty (Free Agent), Bailey Wright (Bristol City - loan), Josh Scowen (QPR) | Out: Dylan McGeouch (Aberdeen), Laurens De Bock (Leeds United - end of loan) Photo: Clive Brunskill
22. Tranmere Rovers
In: Peter Clarke (Fleetwood Town), Alex Woodyard (Peterborough United - loan), Luke McCullough (Free Agent) | Out: None Photo: Lewis Storey
23. Wycombe Wanderers
In: David Stockdale (Birmingham City - loan), Jason McCarthy (Millwall - loan) | Out: None Photo: Alex Morton