Hugh
Dear Hugh: Colorado residents and visitors alike may purchase up to one ounce of cannabis at a time, once a day, but may possess up to two ounces of marijuana at a time, while registered medical marijuana patients are allowed to purchase two ounces. Confusing, we know.
The one-ounce possession limit was created when Colorado first legalized recreational cannabis in 2012, with lawmakers increasing it to two ounces in 2021. However, the state licensing authority is in charge of cannabis purchasing limits, and those still haven't changed.

Colorado dispensaries can't sell recreational customers more than one ounce of flower per day.
Scott Lentz
Technically, the one-ounce purchase limit applies to an entire day, but as suggested in your question, there’s nothing really stopping someone from purchasing the limit at one recreational dispensary, then walking into another down the street for more shopping. These days, dispensaries won’t just wink and smile at customers who purchase an ounce and walk back in moments later for more bud, as some once did. That being said, there’s still no system set up to track recreational customers’ activity.
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