The Hills star, 23, told Us all about the five must-have essentials inside her Miu Miu studded leather handbag, which included her stuffed Balenciaga wallet and her Twitter-friendly Blackberry.
What else can't she leave home without?
"Sunglasses," she says, holding up her $60 pair of Marc by Marc Jacobs shades. "I'm from L.A.!"
The star also packs dozens of lip glosses and mini perfume bottles by Jacobs and Stella McCartney because "you never know what boy you're going to meet" and you "have to smell good."
Pratt doesn't just love her carry-alls. She personally designed three of the purses she wears on the upcoming season of The Hills. To check them out, tune into the hit MTV reality series, which premieres on Tuesday.
