Anything is possible, depends on how much money they want to throw at it. Climbing up to the third division (fourth tier) is definitely do able, have a look at Wrexham FC (Ryan Renolds team). They've done two leagues in two years and will be in the 2nd divison (3rd tier) next year. Entering the top 4 professional leagues is when you start to get the regulations. Capacity, facilities, Safety, Lighting Their ground will need to upgraded or it would be probably easier if they just relocate to a new stadium. The rules will become even more onerous once you get to the top 2 leagues. i.e all seater stadiums with a minimum capacity of 21,000 That's just the infrastructure, then you get to the players. They will need to start spending on some good players and a good manager, i.e entice quality players from higher divisions to come down and join them. More money. Throwing money at players and managers often doesn't actually work and you go down as fast as you came up. Lets not forget the owners, who can also balls things up. Wrexham FC is a good example to have a look at with what you can do with a manager who knows what he's doing (and should really be at a team far higher) and players who should also be a better clubs. One of the hardest things is to hang on to your best players and manager when the big money comes along and tries to lure them away for a shot at playing in the Premier league of first division.