An Iris Deactivation Code (IDC for short) is an authorization code given to Starfleet personnel and their allies which allows the SGC to recognize inbound Stargate travellers as friendly. Since the Federation use an iris to block all incoming wormholes, an IDC is necessary for a traveller to gain access through the Stargate. They are used by both Stargate Command and the Atlantis Expedition.

IDCs are transmitted using Garage Door Openers, a wrist-mounted transmitter with a keypad to enter the relevant code. The signal is received by a computer which identifies its origin, and an "All Clear" signal is transmitted back once the iris is open; otherwise, the GDO returns a "Do Not Proceed" message. Each offworld team and Earth's various allies are assigned a specific code. If a code is potentially compromised, a new code is issued, though the system will still recognize old codes. (SG1: "Foothold", "Gemini")

Trivia

• Jack's iris deactivation code, prior to the events of "Unnatural Selection", was 903224637.
• Samantha Carter's iris deactivation code early in the series is seen to be: 1631293. ("The Tok'ra, Part 2")
• Typhuss James Kira's iris deactivation code in the 2380s and 2390s, is 4123864397. His iris deactivation code in the 2360s and 2370s was 64760198.