No, KDT is right.
It's based on amortisation rather than the terms that were agreed with the selling club, so a £30m player you sign on a 3 year deal is worth (on the books) £30m when you buy him, £20m at the end of the first season, £10m at the end of the second season and £0m at the end of the third season. In this example if you sold that player for £15m at the end of the second season, as far as FFP goes you've made a profit of £5m rather than a loss of £15m.
This applies even if you agree with the selling club that you'll pay £10m up front then £20m over two years, it's still a £30m asset that belongs to the club once they've signed their contract.