As long as you're a rewards member at the green or gold level and you don't exit the store after your original order, you qualify for the free refills, according to the coffee chain's policy.
The refill drinks must be one of Starbucks' lower-priced drinks, however, which include brewed coffee, iced coffee, hot tea and iced tea. And you must purchase the drink on a registered Starbucks card at the green or gold level.
Rewards members reach green level when they have accumulated five stars, which is equal to five Starbucks purchases. Gold level is achieved by accumulating 30 stars in 12 months.
Seattle attorney Melody Overton, who runs the blog StarbucksMelody.com, says the refill policy is one of Starbucks' biggest "problem policies" because baristas often don't follow it.
"Yes, you can buy a Grande Cool Lime Refresher, and ask for a Iced Passion Tea in that cup as a refill," she wrote on her blog recently. "I was at the Corson & Michigan Starbucks about one week ago, and did just that. A Starbucks barista (Hannah?) said 'yes' without any wincing, questioning, or anything at all. It should be that way everywhere."