Former striker Darren Bent's failure to make his full international debut for England against Poland means Town will have to wait until 2006 for any additional cash on top of the £2.5 million Charlton paid for his services this summer.
Bent was again an unused sub as England secured top spot in their World Cup qualifying group with a 2-1 victory over the Poles.
Town will receive a top-up reported to be £200,000 after Bent's first appearance for England in a competitive match and the same figure after his second.
The Blues must now wait until the World Cup proper in June and July 2006 at the earliest for their next chance of receiving further cash from the Addicks.
Elsewhere, keeper Lewis Price wasn't even on the bench as Wales beat Azerbaijan 2-0 in Cardiff. Price picked up a hip injury in training towards the end of last week but the Blues are confident he will be fit enough to face Reading at the Madejski Stadium on Sunday.