Town chief executive Derek Bowden has revealed that the Blues will receive £200,000 on each of Darren Bent's first two competitive England appearances, double the figure previously reported. Bent looks certain to be named in Sven-Goran Eriksson's squad for Germany.
Bowden told the club site: "We would get a substantial fee if Darren plays in Germany.
"We had various additions built in to the original agreement with Charlton and the club will pick up £200,000 if Darren plays in a World Cup or European Championship game, and the same again if he plays in a second match.
"It will be an unbudgeted windfall ahead of the new season."
Bent left Portman Road for the Valley for an initial £2.5 million last summer.