Cinderford Town were left with "no option" but to accept promotion to the Southern League Premier Division, chairman Stuart Tait has said.
The Gloucestershire club initially refused promotion after winning the Southern Division One South & West title, over financial concerns.
The club voted "unanimously" to accept going up, at a meeting on Wednesday.
A Football Association appeal board found that Cinderford had "no discretion to refuse promotion".
After Cinderford's initial rejection of promotion, it was decided to move Evesham United from the Southern League Division One South & West to the Northern Division One South, to balance the number of teams in the respective divisions.
Evesham appealed that decision and it was overturned by an FA appeal board on Wednesday.
In a "final and binding" decision, the appeal board said the regulations meant Cinderford - who have outstanding HMRC debt of £30,000 - must be promoted.
Evesham will now remain in Southern Division One South & West for 2016-17.
All change in both the North and South
Cinderford's promotion means that Lincolnshire side Stamford AFC, who finished fourth from bottom in the Northern Premier League, will now be relegated.
That, in turn, means that Corby Town will be switched from the Southern League to the Northern Premier, to accommodate Cinderford in the Southern League.
"We were forced to do it. We had no option. Go up, or go out of (resign from) the league," Tait told BBC Points West.
"With what has gone on in the last few weeks at the club, with the community coming together, there is a big, strong belief that we can make it work now.
"The FA, in their wisdom, have decided to force us into further bills. We've had a business plan in action for the last couple of weeks.
"We've had to alter that. Can we take on that extra burden? It was decided, yes, we can."
Can Cinderford rebuild?
Cinderford were unbeaten at home all season and won the league with 96 points but, after initially rejecting promotion, their manager and many of the title-winning side left the club.
"You never know, now we've gone into a higher league, some of them may come back," Tait added.
"I am really excited now. We want to achieve something. We were knocked for lack of ambition but that ambition and passion is still there."
Defender Josh Nelmes, who played for the club in 2015-16, added to BBC Points West: "It think it is going to be hard to recover from.
"Hopefully we can find enough players to play the level. If I was to leave, which I'm not 100% sure on yet, I'd still support the club."