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:
1. Accrington Stanley
In: None | Out: None Photo: Nathan Stirk
2. AFC Wimbledon
In: Mads Bech Sorensen (Brentford - loan) | Out: None Photo: Warren Little
3. Blackpool
In: Jordan Thorniley (Sheffield Wednesday), Kiernan Dewsbury Hall (Leicester City - loan), James Husband (Norwich City), Chris Maxwell (Preston North End), Connor Ronan (Wolves - loan), Gary Madine (Cardiff City), Marc Bola (Middlesbrough - loan) | Out: Ryan Hardie (Plymouth Argyle - loan), Jordan Thompson (Stoke City), Nick Anderton (Carlisle United), Michael Nottingham (Crewe Alexandra - loan), Christoffer Mafoumbi (Morecambe - loan) Photo: Mark Robinson
4. Bolton Wanderers
In: Muhammadu Faal (Enfield Town), Ethan Hamilton (Manchester United - loan), George Thomason (Longbridge Town), Brandon Fleming (Hull City - loan), Toto Nsiala (Ipswich Town - loan) | Out: None Photo: Gareth Copley