Heidi Montag has decided to make her recent separation from husband Spencer Pratt legal.

The Hills star filed for legal separation from Pratt on Tuesday morning at the Santa Monica Courthouse, citing irreconcilable differences, TMZ reported.

Since Montag did not file divorce papers, she and Pratt remain married. However her earnings will now become separate property as of Tuesday, according to TMZ, which added under the filing's "community assets and debts" section Montag wrote, "No such assets or debts."

"As far as she's concerned the marriage is over," a source told RadarOnline, which also reported the filing.

"She's not quiet ready to file for divorce. She had great concern for her finances; Spencer has been spending what she considers to be her money."

Montag -- who wed Pratt in April 2009 -- moved out of the Pacific Palisades, CA home she shared with him late last month, but didn't make any legal filings. Instead, she stated the couple is "working on things" and she "just needed some space."

Multiple sources have recently claimed that Montag and Pratt's split is a publicity stunt because The Hills is currently in the midst of airing its final season and the couple has no new projects on the horizon.

The Hills co-stars Audrina Patridge and Lauren "Lo" Bosworth and The City star Whitney Port also recently stated they doubt Montag and Pratt's split is for real.

Montag initially tried filing for separation in Malibu, however that city's court does not handle divorces -- causing her to go to Santa Monica, TMZ reported.