Change is in the air for North Coast food trucks.

A new state rule, which goes into effect Tuesday, will permit vendors to post flat-rate prices for the food they sell that include sales tax.

So, instead of having to add the sales tax to prices at the spot of the transaction, vendors can figure out how much they owe in taxes later.

"The point was to streamline the process for everybody," said Brian Miller of the California Board of Equalization, the public agency charged with the administration of taxes and fee collection. "The ... number of food trucks in California has grown substantially and we wanted to make it easier on everybody. "

Currently, trucks have to post signs saying the tax is included in prices or add the tax to the listed price, leading to different prices based on where the truck is parked when the sale is made. Now, they can charge one price — say $5 for a sandwich — no matter where they sell it and calculate how much they owe when they pay their sales tax.

And, said state officials, customers won't have to reach into their pocket for extra change.

"In making the process simpler for the vendors, we're also helping consumers too," Miller said.

There are about 4,000 mobile food vendors registered with the state, he said, a number that has been growing steadily each year. Unlike a brick and mortar restaurant, mobile food trucks can change their sales tax rate several times in one day.

Local vendors, even some who didn't know about the new rules, hailed the idea in principle but wanted to wait and see how it worked in practice.

"I can see how it would make it easier for the moment (of the transaction)," said Yvette Cabrera, manager of El Roy's Mexican Grill, which has trucks in Petaluma and west Santa Rosa. "I hope we aren't faced with having to fill out more paperwork in the end."

(You can reach Staff Writer Elizabeth M. Cosin at 521-5276 or