CHECKING I/D: Sarah Jessica Parker’s P.R. Firm is Moving to a Posh Penthouse in SoHo.

The p.r. firm that reps Sarah Jessica Parker has found a sexier site in the city. I/D Public Relations had been subletting a small office from Greene Street Films at 9 Debrosses St. in TriBeCa.

Now the team that also pitches Sean Penn and Mira Sorvino has leased a 2,800-square-foot posh SoHo penthouse at 155 Spring St. Christopher Owles and Bruce Sinder of Sinvin Realty represented both sides of the five-year deal.

Sinvin had been asking $42 a foot for the sixth floor space, which adjoins neighbor Bonne Bell cosmetics. The building is dog-friendly-a plus for Winston, an I/D partner’s pug. The offices will also provide a bird’s-eye view of Meg Ryan’s new penthouse condo on nearby West Broadway.