BBC Sport outlines the promotion and relegation issues - and the race for Europe - in England and Scotland.
PREMIER LEAGUE
The top three teams qualify for the Champions League group stage, with the fourth-placed team entering the preceding play-off round.
English clubs have three places in the Europa League - for the FA Cup winners, Capital One Cup winners and fifth-placed Premier League side.
Chelsea were the first English side to book their place in Europe by
winning the League Cup, and are now assured of a top-four place and thus will play Champions League football next season. Chelsea's Europa League slot as Capital One Cup winners will be transferred to the team in sixth. However, if Arsenal finish sixth and win the FA Cup, they will qualify for the Europa League through their league placing, with the team in seventh inheriting their slot for winning the FA Cup.
Jose Mourinho's side will be Premier League champions by Wednesday, 29 April if they beat Arsenal and Leicester.
Should Arsenal win the FA Cup and finish in the top four, their Europa League place will be allocated to the next highest club in the Premier League that has not yet qualified for the tournament, rather than to the beaten finalists.
The top three countries in Uefa's Respect Fair Play league get an extra Europa League place.
The bottom three Premier League teams will be relegated to the Championship.
CHAMPIONSHIP
The champions and runners-up will be promoted to the Premier League, and the next four teams will contest the play-offs.
Watford, Bournemouth, Middlesbrough and Norwich have all secured at least a play-off place - with the automatic promotion places between those four teams - while Derby, Ipswich, Brentford and Wolves will scrap for the two remaining play-off berths.
Table-topping Watford will be promoted if they beat Brighton on Saturday (12:15 BST) and other results go their way. Should they win and Bournemouth and Middlesbrough both lose, the Hornets would be promoted. Equally, defeat for one of those two, coupled with Norwich failing to win, would also be sufficient.
Bournemouth can be all but promoted if they beat Bolton on Monday, should Middlesbrough lose and Norwich fail to win on Saturday. Their goal difference is 15 better than Boro.
Derby will clinch a play-off place if they beat Millwall or match the results of Brentford and Wolves. Their superior goal difference means if they lose, they are almost guaranteed the top six so long as their two rivals do not both win.
Ipswich will seal their top-six spot if they better the results of Brentford and Wolves.
The bottom three teams will be relegated to League One.
Blackpool were the first Football League team to go down this season, after fellow strugglers
Rotherham beat Brighton 1-0on 6 April.
The further relegation places are slightly complicated by 21st-placed
Rotherham's three-point deduction. They have until 1 May, the day before the final fixtures of the season, to appeal.
Wigan will be relegated if they fail to beat Wolves and if Rotherham beat Norwich.
Millwall will join them if they lose to Derby and the Millers win. The Lions' goal difference means they will be practically down if they draw and Rotherham win.
LEAGUE ONE
The second spot is realistically between Preston and MK Dons, who are each guaranteed one of the four play-off places at least along with Swindon.
Preston will be promoted if they beat Swindon and MK Dons lose to Rochdale.
Sheffield United will seal a play-off spot if they avoid defeat at Leyton Orient or if Rochdale do not win. Chesterfield will do the same if they win and Dale do not.
Colchester will join them if they lose at Fleetwood, Crewe and Crawley both win their games and Port Vale avoid defeat.
Notts County and Leyton Orient can both go down if they lose, Crewe win and Crawley avoid defeat - or if they draw, Crewe and Crawley both win and Port Vale avoid defeat.
LEAGUE TWO
The top three teams will be promoted to League One, while teams finishing from fourth to seventh will contest the play-offs.
Burton were the first team to secure promotion thanks to a
2-1 win at Morecambe on 18 April. Jimmy Floyd Hasselbaink's side will be crowned champions if they beat Northampton and Shrewsbury fail to overcome Cheltenham.
The other two automatic places are between Shrewsbury, Wycombe, Southend and Bury, who are all assured of at least a play-off place.
Shrewsbury can be promoted if they beat Cheltenham, or if Wycombe and Southend both fail to win.
Wycombe's goal difference means they will on the brink of League One if they beat Morecambe, Southend lose and Bury fail to win.
Stevenage will seal a play-off place if they beat Carlisle, or match the result of either Plymouth or Luton.
The bottom two teams - two of Hartlepool, Cheltenham and Tranmere - will be relegated to the Conference Premier (or the National League as it will be called next season).
Tranmere will be relegated after 94 years in the Football League if they lose and Cheltenham win, or if they fail to beat Plymouth and Hartlepool win.
Cheltenham will go down if they lose to Shrewsbury and Hartlepool beat Exeter.
CONFERENCE PREMIER
The champions will be promoted to League Two, with teams finishing from second to fifth contesting the play-offs for the second promotion place.
Leaders Barnet are one point clear of Bristol Rovers and will win the title if they beat Gateshead in their last match of the season on 25 April. If Barnet slip up, Bristol Rovers will go up if they defeat Alfreton.
The title chasers and Grimsby are guaranteed at least a play-off place and will be joined by two from Eastleigh, Macclesfield and Forest Green.
Macclesfield need to win and hope that Eastleigh lose or Forest Green fail to win.
The bottom four teams will be relegated, and replaced by the champions and play-off winners of the Conference North and South divisions.
AFC Telford United became the first team in England's top five divisions to be relegated on 4 April after they could only
draw 1-1 with Kidderminster.
Welling will be practically safe with a win against Southport (barring a 14-goal swing on goal difference). Alfreton need to better their result to stay up. Southport can only go down if they lose and Alfreton win, with an eight-goal swing.
SCOTTISH PREMIERSHIP
The Scottish Premiership will split in half after all teams have played 33 games, with the top six and the bottom six playing the other sides in their 'half' for a fourth and final time.
The champions will enter the Champions League in the second qualifying round.
The teams finishing second and third qualify for the Europa League along with the Scottish Cup winners.
The cup winners enter the competition in the second qualifying round, and the second and third-placed teams in the first qualifying round.
Should Inverness beat Falkirk in the final and finish in the top three in the league, the fourth-placed team would also qualify.
The top three countries in Uefa's Respect Fair Play league get an extra Europa League place, which is given to the highest-placed team in the top flight's Fair Play table that has not yet qualified for Europe.
The bottom side will be relegated to the Scottish Championship, while the 11th-placed side will face the winners of the Championship play-offs over two legs, with the losers condemned to a place in the second tier next season.
St Mirren can, at best, finish 11th and will be relegated if they fail to beat Kilmarnock and Motherwell win at Hamilton.
SCOTTISH CHAMPIONSHIP
The third and fourth-placed teams will meet in the first round of the play-offs, with the winners playing the division's second-placed team. Whoever emerges victorious from that two-legged encounter will face the second bottom side in the Premiership - again on a home and away basis - with a spot in the top flight the prize.
Rangers and Hibernian will be joined in the play-offs by either Queen of the South or Falkirk.
The bottom club will be relegated to League One, while the ninth-placed team will enter a play-off with three League One sides.
SCOTTISH LEAGUE ONE
The champions will be promoted to the Championship. The next three teams will enter a play-off with the ninth-placed Championship side.
Leaders Stranraer, as well as Morton and Forfar, are assured a place in the play-offs at least.
Bottom team
Stirling Albion were relegated to League Two after
losing 2-1 at Brechin on 11 April, while the ninth-placed team - Ayr or Stenhousemuir - will enter a play-off.
SCOTTISH LEAGUE TWO
Albion Rovers wrapped up the title and promotion with a
3-2 win at Clyde on 18 April, coming back from two-goals down.
The teams finishing second, third and fourth will enter a play-off with the ninth-placed League One team.
Queen's Park and Arbroath are already sure of play-off places.
Montrose, who are guaranteed to finish bottom, will enter a play-off against the winner of a play-off between Highland League champions Brora Rangers and Lowland League title winners Edinburgh City for the final place in next season's League Two.