LOS ANGELES — Netflix, the largest subscription streaming service, is testing new prices based on the number of people who can use an account, a move that could force customers to pay more for additional family members.

Netflix is offering some new customers plans that provide access on as many as four screens, letting household members watch different shows at the same time. The monthly prices range from $6.99 to $11.99, according to an offer posted on the Los Gatos, Calif.-based company’s website.

If successful, the pricing plans could be expanded to more customers. The test suggests Netflix, with more than 40 million subscribers, is looking for ways to curb account sharing while providing viewers with more ways to watch, just as cable TV operators rent additional set-stop boxes to households.

“I am sure that they have the ability to monitor device use,” said Michael Pachter, an analyst at Wedbush Securities in Los Angeles, who has an underperform rating on the stock. “I admire their resolve to try to combat piracy. This is an ingenious solution.”

The standard Netflix streaming service costs $7.99 a month, according to the company’s website. The DVD by mail subscription starts at $7.99 for one disc at a time.

One possible risk for the company is that customers downgrade to the one-screen, $6.99-a-month option rather than pay for a higher level of service.

“If consumers who would have taken the $7.99 plan now sign up at $6.99, that all comes out of their profit margin,” said Richard Greenfield, an analyst at BTIG who has a neutral rating on the stock.