Jackie Brown is a flight attendant for a small Mexican airline. To make ends meet, she smuggles money from Mexico into the United States for Ordell Robbie, a black-market gun runner living in the Los Angeles metropolitan area under the ATF's close watch, forcing him to use couriers. Ordell learns that another of his couriers, Beaumont Livingston, has been arrested. Assuming that Livingston will become an informant in order to avoid jail time, Ordell arranges for bail with bondsman Max Cherry, then coaxes Livingston into a car trunk and murders him.
Acting on information Beaumont had already shared, ATF agent Ray Nicolette and LAPD detective Mark Dargus intercept Jackie as she returns to the United States with Ordell's cash and some cocaine that Brown was unaware was stashed in her bag. Initially refusing to cut a deal, she is sent to jail which alerts Ordell that she might also be a threat to inform. Having received payment from Ordell, Max picks up Jackie from the jail and begins to develop an attraction to her. Ordell arrives at Jackie's house intending to murder her but she surprises him by pulling a gun surreptitiously taken from Max's glove compartment. Jackie negotiates a deal with Ordell to pretend to help the authorities while smuggling in $550,000 of Ordell's money, enough to allow him to retire.
To carry out this plan, Ordell is counting on Melanie Ralston, an unambitious, stoned surfer girl with whom he lives, and Louis Gara, a friend and former cellmate. Unaware of Jackie and Ordell's plan to smuggle in $550,000, Nicolette and Dargus devise a sting to catch Ordell during a transfer of $50,000. Unbeknownst to all, Jackie plans to double-cross everyone and keep $500,000 for herself. She recruits Max to assist with her plan and offers him a cut.
In the Del Amo Mall on the day of the transfer, Jackie enters a dressing room to try on a new suit. She has told Ordell that she will swap bags there with Melanie, supposedly passing off the $550,000 under the nose of Nicolette, who has been told that the exchange is to take place in the food court. Instead, the bag she gives Melanie contains only $50,000 and the rest is left behind in the dressing room for Max to pick up. Jackie then feigns despair as she calls Nicolette and Dargus out from hiding, claiming Melanie took all the money and ran.
In the parking lot, Melanie mocks Louis until he loses his temper and shoots her. Louis confesses this to Ordell. Ordell is livid when he discovers that most of the money is gone, and he realizes that Jackie is to blame. When Louis mentions that during the hand-off he saw Max Cherry in the store's dress department and thought nothing of it, Ordell kills him and leaves with the bag. Ordell turns his anger toward Max, who informs him that Jackie is frightened for her life and is waiting in Max's office to hand over the money. A menacing Ordell holds Max at gunpoint as they enter the darkened office. Jackie suddenly yells that Ordell has a gun, and Nicolette jumps from a hiding place and shoots him dead.
Having had her charges dropped for cooperating with the ATF, and now in possession of the money as well as Ordell's car, Jackie decides to leave the country and travel to Madrid, Spain. She invites Max to go along with her, but he declines. Jackie shares a meaningful moment with Max, kisses him goodbye, and leaves as Max takes a phone call. Moments later, Max cuts the call short and seems to contemplate his decision to stay behind as Jackie drives away.

Question: Why does Jackie smuggle money for Ordell?
Answer: She needs to earn more money than her salary pays to live on.