'Vanderpump Rules' Reboot Begins Filming Soon With New Cast

"These are the best days of our lives" ... because TMZ has learned the brand-new cast for Season 12 of "Vanderpump Rules" will begin filming in a few weeks.

Production sources tell us ... the rebooted Bravo series will go into production in early April. We're told the cast is made up of 14 members ... some will be full-time and others will be friends of the cast.

We're told the rebooted version of the long-running series will keep its original formula, which will take viewers inside the hookups, feuds and drama surrounding Lisa Vanderpump's West Hollywood restaurant, SUR. We're told the SUR-vers' homes and lives outside the restaurant will be the meat of the show.

Our sources say the incoming new cast members finalized their contracts last week.

As we reported ... the network told us in November LVP would return for a new season, but would be surrounded by a new cast.

TMZ broke the story ... most of the OG cast members weren't too surprised by the new direction when they were informed of the decision ... especially after the show was put on pause back in April.