I’ve compiled a quick list here of reputable and generally well-regarded tea vendors. I can’t vouch for all of these personally but have done my best to research each thoroughly. The list is pretty brief at the moment but of course open to expansion. Feel free to leave a comment if you’ve had a positive experience with a vendor not on the list!

• Yunnan Sourcing [China], [US] - Highly reputable vendor sourcing from the Yunnan province of China. Generally good-quality tea of all types, and a great starting point for beginners. US website will ship from their Texas warehouse but with somewhat reduced selection.
• Teavivre [China], [US] - Another well-regarded tea vendor sourcing from a variety of regions in China. Also has a US warehouse.
• Upton Tea [US] - US-based vendor that imports tea from all over the world. Particularly recommended for their Indian teas.
• Teabox [India] - Another vendor with a great selection of Indian teas.
• Ippodo Tea [US], [Japan] - Japan-based tea vendor with a large selection of Japanese teas like matcha, gyokuro, sencha, and more.
• Hibiki-an [Japan] - Budget-friendly Japanese tea vendor. Fast and affordable shipping directly from Japan.
• Republic of Tea [US] - Vendor with a large selection of teas in both loose and bagged form. Sources from various countries including China, India, and Japan. Can be found in many grocery stores.
• Harney and Sons [US] - Another vendor with a huge variety of flavored and unflavored teas, though mainly recommended for their black and flavored teas. Offers both loose and bagged forms, and can also be found in many grocery stores.
• Floating Leaves [US] - Very well-regarded specialty vendor specializing in Taiwanese oolong teas, also offering black, puer, green, and white.
• Crimson Lotus [China/US] - Seattle-based vendor sourcing directly from Yunnan, China, specializing in puer tea. Ships mainly from China with some inventory at their Seattle warehouse.
• white2tea [China] - Heavily puer-focused vendor with an expansive selection of raw and ripe puers. Also offers some higher-end black, oolong, and white teas.