Gwyneth Paltrow and Chris Martin are expected to marry within the next three months.
The couple, who last week announced they are expecting their first baby, have applied for a marriage licence.
They turned up at a Santa Barbara courthouse to apply for the licence, which allows them to be married by a judge in Santa Barbara County within the next 90 days.
Pam Smith, a supervisor at the Santa Barbara county clerk/recorder's office, said the license didn't require them to disclose the marriage date.
In an interview with Michael Parkinson last month, Paltrow refused to spill the beans about any future wedding plans with Martin. "I don't know. I hope so," she said. "I'm the wrong person to ask. Ask him."