The microSD format was created by SanDisk. The concept was the brainchild of the CTOs of SanDisk and of Motorola, who believed current memory card formats were too large for phones. It was originally called T-Flash, but just before product launch, T-Mobile sent a cease and desist order to SanDisk claiming they own the trademark on T-(anything) and the name was then changed to TransFlash. After pressure from Toshiba and Panasonic, SanDisks partners in the 3C licensing group of the SDA, SanDisk negotiated to have the new format become a standard administered by the SD Card Association (SDA). The SDA announced the microSD format at CTIA Wireless 2005 on March 14, 2005, and approval of the final microSD specification on July 13, 2005. At launch, the microSD format was available in capacities of 32, 64, and 128 MB. TransFlash and microSD cards are the same; each can be used in devices made for the other.

Considering how small SD cards are, whyd they shrink it even more to create the Micro SD card? To start, the Secure Digital (SD) memory card format evolved from the earlier MultiMediaCard format, borne out of a need for higher memory density and Digital Rights Management resulting from the explosion of devices designed to play digital music. Digital music devices are one thing, but the years that followed saw the physical size mobile phones shrink faster than an ice cube in the summer sun. While the SD format sufficiently met the needs for most of the consumer electronics industry, the seemingly endless wave of miniaturized cell phones meant SD had to be miniaturized as well. The Micro SD card format was created and cell phone manufacturers had a memory card small enough to stick into their ever expanding line of advanced models.