Whether they are pushing for the title, challenging for a Champions League spot or battling to stay up, the January transfer window gives Premier League clubs the chance to strengthen their squads.
Familiar faces such as Nicolas Anelka, Robbie Keane and Thierry Henry could all be returning to these shores, while other transfer targets include La Liga stars Radamel Falcao, Fernando Llorente and David Villa and existing Premier League players Darren Bent and Marouane Fellaini.
BBC football expert Mark Lawrenson looks at each top-flight side and examines who they need to sign or whether they need to put down the shutters to ward off bids for their best players.
What they need in a nutshell: More characters as much as more quality.
Window shopping: A goalkeeper - Liverpool's Pepe Reina would be ideal because he needs a new challenge - and, without doubt, another striker. Not just Thierry Henry, either.
Henry would be great at coaching their forwards but, if he comes back again and plays regularly, that would say a lot about where the club is at the moment, and not in a positive way.
A defensive midfield player with character; a leader. He would not have to be the best player Arsene Wenger has ever signed in terms of skill but they need a bit of grit and determination.
Linked with (Player, age, position and club): Pepe Reina 30, GK (Liverpool) Felix Stoppila Sunzu 23, CB/DM (TP Mazembe) Mapou Yanga-Mbiwa 23, CB (Montpellier) Wilfried Zaha 20, FW (Crystal Palace) Thierry Henry 35, CF (New York Red Bulls) Fernando Llorente 27, CF (Atletico) David Villa 31, CF (Barcelona) Lucas Biglia 26, DM (Anderlecht) Luke Shaw 17, LB (Southampton)
What they need in a nutshell: To sell Darren Bent and add some nous and know-how.
Window shopping: Paul Lambert is building a young side but he is going to have to get two or three experienced heads in there, just to help the kids, because they look short at the moment. Maybe a 'number 10' type of forward who can sit behind Christian Benteke and who they can play through. Robbie Keane, who they signed on loan last January, would again be ideal.
But what they do with Bent could be the key. They could sell him and bring in the two or three players they need with the money. Villa might have to take a hit on the £18m or so they paid for Bent in January 2011 but the deal needs to be done.
Linked with: Derek Boateng 29, CM (Dnipro Dnipropetrovsk) Modou Sougou 27, AM (Cluj) Glenn Murray 29, FW (Crystal Palace) John Guidetti 20, CF (Man City) Robbie Keane 32, FW (LA Galaxy)
What they need in a nutshell: At least one striker, maybe more.
Window shopping: Strikers. At least one and maybe two if Daniel Sturridge is sold and Romelu Lukaku stays on loan at West Brom.
And some more bodies in the centre of their midfield because Oriol Romeu is out for the season, John Mikel Obi is away at the Africa Cup of Nations with Nigeria and I am not sure whether Frank Lampard is part of Rafael Benitez's plans.
Linked with: Marouane Fellaini 25, AM (Everton) Andre Schurrle 22, FW (Bayer Leverkusen) Willian 24, FW (Shakhtar Donetsk) Radamel Falcao 26, CF (Atletico Madrid) Paulinho 24, CM (Corinthians) Fernando Llorente 27, CF (Atletico) Dejan Lovren 23, CB (Lyon) Theo Walcott 23, FW (Arsenal)
What they need in a nutshell: To lock up Leighton Baines and Marouane Fellaini until 1 February.
Window shopping: Their aim for January has to be keeping Fellaini and Baines more than signing anyone. David Moyes will not discuss a new contract until the window closes and, in terms of his future as their manager, it is important they don't sell either of them.
They might also need a new centre-back. Sylvain Distin has come back into the picture because Johnny Heitinga has not had a great season but Distin is 35 now. Joleon Lescott would be ideal if they could take him on loan and do a deal with Manchester City about his wages.
Linked with: Jack Butland 19, GK (Birmingham) Joleon Lescott 30, CB (Manchester City) Salomon Kalou 27, FW (Lille) Kevin Gameiro 25, CF (PSG) Wissam Ben Yedder 22,CF (Toulouse) Scott Sinclair 23, LW (Manchester City)
What they need in a nutshell: Midfielders, with a creative edge.
Window shopping: Midfield is an absolute priority, especially in terms of creative players but also because they will lose defensive midfielder Mahamadou Diarra to the Africa Cup of Nations.
Another striker would be useful and they also need to keep hold of Brede Hangeland at the back. He is out of contract in the summer but is a key player for them and they would not get massive money if they sold him now.
Linked with: William Vainqueur 24, CM (Standard Liege) Lewis McGugan 24, CM (Nottingham Forest) Derek Boateng 29, CM (Dnipro Dnipropetrovsk) Dieumerci Mbokani 27, CF (Anderlecht) Maarten Stekelenburg 30, GK (Roma) Danny Simpson 25, RB (Newcastle)
What they need in a nutshell: Attacking players who fit into Brendan Rodgers's system.
Window shopping: I don't really understand their move for Chelsea striker Daniel Sturridge if he wants to play down the middle because what do you do with Luis Suarez? But it might work if they can convince Sturridge to play on the right or left.
Someone like Newcastle striker Demba Ba would work if the deal was right and, if they got a striker like him, then a 4-2-3-1 formation would be better so Ba can roam up front on his own and Suarez can play in the middle of the three behind him.
They also need a new left-back because I don't think Rodgers fancies Jose Enrique in that position.
Linked with: Asmir Begovic 25, GK (Stoke) Jack Butland 19, GK (Birmingham) Daniel Sturridge 23, FW (Chelsea) Thomas Ince 20, FW (Blackpool) Kevin Gameiro 25, CF (PSG) Theo Walcott 23, FW (Arsenal) Darren Bent 28, CF, (Aston Villa) David Villa 31, CF (Barcelona)
What they need in a nutshell: To ditch 'Super Mario'.
Window shopping: The first thing Roberto Mancini needs to do on 1 January is sell Mario Balotelli. He keeps upsetting the applecart and he is not a good enough player to justify it. I would get him out of the door and bring in another striker.
Micah Richards is on his way back from injury but they might need another centre-back too. Mancini clearly does not fancy Joleon Lescott and Kolo Toure is away with Ivory Coast at the Africa Cup of Nations.
Kolo's brother Yaya will also be going to South Africa and will be a big miss in midfield but Mancini needs Javi Garcia to step up rather than bring anyone else in.
Linked with: Daniele De Rossi 29, CM (Roma) Mamadou Sakho 23, CB (PSG) Pedro Franco 21, CB/CM Millionarios Paulinho 24, CM (Corinthians) Fernando Llorente 27, CF (Atletico) David Villa 31, CF (Barcelona)
What they need in a nutshell: Looking for a left-back, but may wait until the summer.
Window shopping: In the long term, they need a new left-back and Everton's Leighton Baines seems the obvious target, but I cannot see a deal for Baines happening in January, if it happens at all.
So I can only see United doing anything in January if someone for the future, or someone very special, suddenly becomes available, but the latter are few and far between.
Linked with: Asmir Begovic 25, GK (Stoke) Robert Lewandowski 24, CF (Borussia Dortmund) Oscar de Marcos 23, AM (Athletic Bilbao) Kevin Strootman 22, AM (PSV Eindhoven) Fernando Llorente 27, CF (Atletico) Wilfried Zaha 20, FW (Crystal Palace) Theo Walcott 23, FW (Arsenal) Jonathan Tah 16, CB (Hamburg)Ashley Cole 32, LB (Chelsea)Frank Lampard 34, CM (Chelsea)
What they need in a nutshell: New faces in every department.
Window shopping: Centre-back and full-back are the two areas that definitely need strengthening, and it looks like France international Mathieu Debuchy could do that job, but you could add striker and midfielder to that list.
They were guilty of not strengthening in the summer but you cannot blame them for that - after how they did last season and kept that side together everyone was thinking they would be all right, but so many of their players have fallen below the standards they set last campaign.
Linked with: Adam Lallana 24, CM (Southampton) Modou Sougou 27, AM (Cluj) Mathieu Debuchy 27, RB (Lille) Jeremain Lens 24, FW (PSV Eindhoven) Loic Remy 25, CF (Marseille) Jody Lukoki 20, FW (Ajax) Moussa Sissoko 23, CM (Toulouse)
What they need in a nutshell: To add some pace to their front line.
Window shopping: Chris Hughton is saying he is happy with what he has got, and they are in good shape after a poor start, but I would be buying a striker. I don't think he is at all convinced about Steve Morison as a back-up to Grant Holt.
You know what you get from Holt, and Wes Hoolahan plays off him and is a clever player, but Hughton might occasionally want to play somebody with more pace and I don't think Morison fits the bill.
Linked with: Modou Sougou 27, AM (Cluj) Robbie Keane 32, FW (LA Galaxy) Craig Mackail-Smith 28, CF (Brighton) Liam Bridcutt 23, DM (Brighton) Curtis Davies 27 CB (Birmingham)
What they need in a nutshell: Some stomach for the fight.
Window shopping: The right characters are vital but I don't think Harry Redknapp is going to have to spend a fortune to get the players he needs or wants.
Robbie Keane would be tailor-made for QPR and Harry might fancy a bit of Joe Cole and Nicolas Anelka too - and all of those three might be available on loan.
I just wonder if he might want another centre-back too. The name that springs to mind is Michael Dawson, but Tottenham might be reluctant to let him go.
Linked with: Joe Cole 31, AM (Liverpool) Loic Remy 25, CF (Marseille) Darren Bent 28, CF, (Aston Villa) Michael Dawson 29, CB (Tottenham) Robbie Keane 32, FW (LA Galaxy) Nicolas Anelka 33, CF (Shanghai Shenhua) Salomon Kalou 27, FW (Lille) Tim Cahill 33, AM (New York Red Bulls)
What they need in a nutshell: Proven Premier League players ready for a relegation battle.
Window shopping: They need more quality in every area of the team and, if they cannot get the players they need in midfield or at the back, then they need to buy some goals. A new centre-forward is the big one for me, because they have scored a few goals but only when they have been chasing games.
Brian McDermott says he wants Premier League know-how but the difficulty is attracting the players they need. How do you attract that quality if you are rock bottom and well adrift of safety? It will be very hard.
Linked with: Roman Pavlyuchenko 31, CF (Spartak Moscow) Andrey Arshavin 31, AM (Arsenal) Wilson Palacios 28, CM (Stoke) Felix Stoppila Sunzu 23, CB/DM (TP Mazembe) Curtis Davies 27 CB (Birmingham) Joe Cole 31, AM (Liverpool)
What they need in a nutshell: A safe pair of hands.
Window shopping: An experienced Premier League goalkeeper would make a massive difference to them.
They were linked to Tottenham's Brad Friedel, who is a great character and a great personality and someone like Paulo Gazzaniga would learn a lot from him too. But any move looks to have been scuppered after he signed a new contract with Spurs until 2014.
They have improved at the back of late but a solid no-frills 'head it, kick it' centre-back would definitely help as well.
Linked with: Brad Friedel 41, GK (Tottenham) Paul Robinson 33, GK (Blackburn) Jack Butland 19, GK (Birmingham) Scott Dann 25, CB (Blackburn) Michael Dawson 29, CB (Tottenham) Matt Phillips FW, 21 (Blackpool) Gary Hooper CF, 24 (Celtic)
What they need in a nutshell: A new pair of full-backs and to keep their goalkeeper.
Window shopping: Blackburn's left-back Martin Olsson would be the perfect fit, because he can play anywhere down that flank, and somebody similar on the right too.
That apart, I think they are all right. Stoke boss Tony Pulis will probably be aware that a lot of bigger clubs are looking at goalkeeper Asmir Begovic but I cannot see them selling him in January unless they get a huge offer.
Linked with: Luke Murphy 23, AM (Crewe Alexandra) Faouzi Ghoulam, 23 LB (St Etienne) Martin Olsson 24, LB (Blackburn)
What they need in a nutshell: A centre-back to tighten up their defence.
Window shopping: Sunderland have been short of goals but I think they have bigger problems in defence. They are in serious need of a new centre-back because Wes Brown has not been fit and John O'Shea has been poor.
Their other worry at the back is that Tottenham might recall Danny Rose from his loan but, if they can keep him, and tighten up in the middle then they are not a million miles away from being a good side.
Linked with: John Guidetti 20, CF (Man City) Gary Hooper 24, CF (Celtic) Sylvain Distin 35, CB (Everton) Tim Cahill 33, AM (New York Red Bulls) Albert Bruce 18, CM (Legia Warsaw) Andreas Granqvist 27, CB (Genoa) Joel Obi 21, CM (Inter Milan)
What they need in a nutshell: Someone to chip in with some goals.
Window shopping: I am expecting them to strengthen because the chairman Huw Jenkins is not one for standing still.
I don't think they need a lot, though - maybe another centre-back and someone to give Michu a bit of support in terms of goals.
They have got Danny Graham to come into their attack so that is not imperative, but maybe they could get another deep-lying striker, who, like Michu, can drop deep or play further forward.
Linked with: Mark Davies 24, CM (Bolton) Craig Dawson 22, CB (West Brom) Albert Adomah 25, FW (Bristol City) Marcos Alonso 22, LB (Bolton)
What they need in a nutshell: To increase their options up front.
Window shopping: Another striker who is a bit different from Emmanuel Adebayor and Jermain Defoe could be useful. They are maybe another club that might be looking for a deeper-lying striker to play off either of those two.
With midfielder Scott Parker and left-back Benoit Assou-Ekotto getting back to full fitness I think they are generally in good shape elsewhere, but a bit of competition up front could do them some good.
Linked with: Joao Moutinho 26, CM (Porto) Dieumerci Mbokani 27, CF (Anderlecht) Willian 24, FW (Shakhtar Donetsk) Fernando Llorente 27, CF (Atletico) Younes Belhanda 22, AM (Montpellier) Lewis Holtby 22, AM (Schalke)
What they need in a nutshell: To fend off bids for their best players.
Window shopping: Baggies boss Steve Clarke says he does not think January is a good time for business and I think he is in the same shoes as David Moyes at Everton in that he does not want people to come in and buy his players.
The likes of Youssouf Mulumbu, Claudio Yacob and Shane Long will all have attracted attention.
Linked with: Obafemi Martins 28, CF (Levante) Tony Watt 18, CF (Celtic)
What they need in a nutshell: A striker and a tricky right-sided player.
Window shopping: Sam Allardyce has been quite vociferous about his need to bring in players and one of them will definitely be a striker. Andy Carroll just has not played much at all because of injury and, while Carlton Cole is a serious handful on his day, he is not consistent enough.
Marouane Chamakh and Nicolas Anelka are some of the names mentioned as potential targets. In the past, Allardyce has been quite creative in terms of the players he has managed to sign, so it will be interesting to see who he brings in.
I also think he might look for a player similar to Matt Jarvis who can play on the right and deliver crosses from that flank too.
Linked with: Jack Butland 19, GK (Birmingham) Miralem Sulejmani 23, FW (Ajax) Salomon Kalou 27, FW (Lille) Marouane Chamakh 28, CF (Arsenal) Nicolas Anelka 33, CF (Shanghai Shenhua) Loic Remy 25, CF (Marseille)
What they need in a nutshell: Keep James McCarthy and hope Arouna Kone is back soon.
Window shopping: The Latics have already set up deals for hard-working Honduras midfielder Roger Espinoza and Manchester United and Chile striker Angelo Henriquez, and I doubt they will be the only January arrivals.
Arouna Kone is going to the Africa Cup of Nations with Ivory Coast so Wigan will be short up front while he is away. They don't need to replace him, but do need to hope he is back fit, and quickly.
Another striker, Franco Di Santo, is out of contract in the summer but there is no way they will sell him in January because they know that would decrease their chances of staying up.
It is the same with James McCarthy, who is interesting a few clubs. It would take massive money to get him now because he will be key to Wigan's survival.
Linked with: Jeremain Lens 24, FW (PSV Eindhoven) Angelo Henriquez 18, FW (Man Utd)