In November, Lumley revealed that she was keen to return to the sitcom.
The actress has now told Hello magazine that she will begin work on new instalments this summer.
"In late August I start filming on three episodes of Absolutely Fabulous, which we are all ecstatic about," she said.
A BBC spokesperson told The Guardian: "We're putting the finishing touches to the deal to bring it back and as soon as we're in a position to confirm it we will."
However, Lumley said that she has no idea what will happen when the show returns, saying: "Miss [Jennifer] Saunders has been so busy writing Uptown Downstairs Abbey for Comic Relief and also Spice Girls: The Musical, I don't think she's started [the script]!"
Lumley has previously said that she "adored" working on Absolutely Fabulous.
Watch a selection of the best bits of Absolutely Fabulous below: