Ryan Lock, who was 20 and from Chichester, West Sussex, was killed on 21 December during a battle for the IS stronghold of Raqqa.
After his death his body had been in the hands of Islamic State militants.
The BBC has been told it has now been recovered and taken to north-east Syria for an official autopsy.
Ryan Lock, who was a chef, had no military experience before travelling to join the Kurdish armed fighting forces known as the YPG in August.
He had told friends and family he was going on holiday to Turkey.
He became the third British man to die fighting with the Kurds against so-called Islamic State.
Mark Campbell, a pro-Kurdish rights activist from KurdishQuestion.com, said: "Ryan's remains are now awaiting repatriation to the UK."
He added: "It is hoped that with the support of the Kurdistan regional government authorities and the UK consulate in Erbil that the process will be able to proceed without delay, although due to the political complexities of the region we expect the process may take some time."
Ryan Lock's parents, who are from Chichester, West Sussex, and Havant, Hampshire, were said to be extremely concerned about the return of their son's remains to the UK.
The father of Konstandinos Erik Scurfield, the first British man to die fighting against IS with the Kurds, visited Ryan Lock's father.
Chris Scurfield told the BBC that his own son's repatriation was paid for by the Kurds and says that they will do the same for Ryan Lock.
"As the Lock family face their son's repatriation, they will experience the British government's kind assurances of help, but only the Syrian Kurds will truly honour their fallen son with practical help and logistical assistance."
A Foreign Office spokesman said: "The UK has advised for some time against all travel to Syria.
"Anyone who does travel to these areas, for whatever reason, is putting themselves in danger."
The body of a British man killed fighting in Syria has been recovered from so-called Islamic State territory, according to Kurdish activists.