A fifth run of episodes has already been commissioned by Channel 4.
Linehan has now told Chortle that he will try to write the instalments this year but suggested that the show would not continue with a sixth series.
"I think one more series to really say goodbye to the characters and the fans," he said. "I'm not rushing into it because I don't want it to be a zombie series where the show is dead but its body is still moving around."
The fourth series of The IT Crowd aired last summer, finishing on a record high in the ratings. The show's star Katherine Parkinson was nominated for a BAFTA at last weekend's ceremony but lost out to Jo Brand.
Last August, Linehan claimed that an American version of The IT Crowd was still in development.