Q. Dear Rov; One that has a basement or a garage one does not want to clean for Pesach and it will be closed completely, does he have to sell in a Mechira Mukdemes (Selling it to a Gentile, the day before Erev Pesach)?
A. Mishna Berura (436: 32) quotes different opinions. Mekor Chaim and Chayei Adam maintain that if they will only be sold on Erev Pesach in the morning, they have to be searched for chametz on the night before as is done with the rest of the house.
However Binyan Olam (20) asserts that no Bedika is needed as the fact that it will be sold tomorrow is in itself tantamount to keeping the chometz one finds until tomorrow to be burned, or the chometz one still want to consume until tomorrow morning, Mishna Berura also quotes that the Chassam Soffer (131) and Eishel Avrohom are lenient. He adds that he should specify that not only he sells that area, but also any chometz therein. He also adds that it is preferable to do an early sell on the thirteen of Nissan.
Horav Aharon Miller Shlit’a also advises to do an early sell. Horav Shlomo Miller’s Shlit’a opinion is similar.
Rabbi A. Bartfeld as revised by Horav Dovid Pam, Horav Aharon Miller and Horav Chanoch
Ehrentreu Shlit’a