Hidden Phone Codes Revealed For Android And iPhone

Gregory Zuckerman
By Gregory Zuckerman
Technology
6 Min Read

Curious users are rediscovering a trove of secret phone codes that unlock diagnostic tools and network settings on both Android and iPhone. Long used by carriers and technicians, these short sequences can reveal your IMEI in seconds, check whether call forwarding is active, or display live signal strength in dBm. Below are 14 vetted codes, what they do, and why they matter—plus critical safety notes before you dial.

What These Hidden Phone Codes Do and How They Work

Most of these are MMI or USSD codes. Some run locally on your device to open diagnostic menus; others query your carrier’s network to show the status of features like call waiting. The GSMA notes that identifiers like the IMEI help carriers track devices and block stolen phones, while the FCC recommends keeping your IMEI handy if your device is lost or needs unlocking. Not every code works on every phone or plan, but many function across major networks and regions.

Table of Contents
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14 Secret Phone Codes You Can Use on Android and iPhone Now

  1. *#06# — Instantly displays your IMEI; on eSIM-capable phones you’ll also see EID and multiple IMEIs for dual SIMs. Useful for warranty checks, carrier unlocks, and theft reports.
  2. *3001#12345#* (iPhone) — Opens Field Test Mode. You can view real-time signal strength in dBm (lower is better; for example, -85 dBm is stronger than -105 dBm), LTE/NR bands, and cell tower metrics that radio engineers rely on.
  3. *#*#4636#*#* (Android) — The hidden “Testing” menu. See phone info, network type, service state, Wi‑Fi usage, and app statistics. Handy for diagnosing flaky 5G or VoLTE issues.
  4. *#21# (GSM/iPhone) — Checks unconditional call forwarding status. If your calls mysteriously skip your phone, this reveals whether a divert is active at the network level.
  5. *#67# (GSM/iPhone) — Shows forwarding when your line is busy. Great if calls jump to voicemail while you’re on another call.
  6. *#62# (GSM/iPhone) — Displays forwarding when your device is unreachable (no signal or powered off). Travelers use this to confirm voicemails or alternate numbers will catch missed calls.
  7. *#61# (GSM/iPhone) — Shows forwarding when calls go unanswered, plus the ring time before voicemail. Useful for fine‑tuning how long your phone rings.
  8. ##004# (GSM/iPhone) — Cancels all conditional forwarding (busy, unreachable, no answer) in one go. If you experimented with diverts and want to revert, this is the reset switch.
  9. *#43# / *43# / #43# (GSM/iPhone) — Check, enable, or disable call waiting. If you often miss second calls or support lines, toggling this can make a big difference.
  10. *#31# (GSM/iPhone) — Shows your caller ID presentation status. For a one‑off blocked call in the US, prefix the number with *67; some GSM networks use #31# before the number to hide and *31# to show.
  11. *5005*25371# and *5005*25370# (iPhone) — Check and toggle test alerts capability used by government/emergency services in some regions. This does not trigger an alert; it displays status. Availability varies by carrier and country.
  12. *#*#426#*#* (Android) — Google Play services diagnostics. Shows connection status, GCM/FCM heartbeat, and latency—useful for push notification troubleshooting.
  13. *#*#2664#*#* (Android) — Touchscreen test. Draw lines to verify edge and multi‑touch accuracy before you declare your display defective.
  14. DANGER: *#*#7780#*#* (Android factory data reset) and on some Samsung models *2767*3855# — These can wipe apps, settings, and data immediately. Do not enter unless you intend to erase the device. Back up first.

Safety and compatibility considerations before using codes

Results depend on your device, carrier, and region. Some codes are disabled by specific networks, and manufacturer overlays can change what appears. If a code returns “Failed” or no response, check your plan features or use the equivalent setting in your Phone app. Remember that several Android diagnostics are OEM‑specific, while iPhone field test screens can vary by iOS version.

Be especially cautious with any reset or firmware-related code. Security researchers and device repair pros emphasize the same rule: if you don’t fully understand a code’s effect, don’t run it. It’s safer to confirm via official Settings menus or carrier support.

Four iPhones in white, orange, and two shades of blue, arranged in a row against a clean white background.

Why These Phone Codes Matter for Everyday Users

In the real world, these shortcuts save time. Field Test Mode helps pinpoint dead zones when your maps show full bars but calls drop; IMEI display speeds up theft reports and unlock requests; forwarding checks stop support calls from vanishing into voicemail. Secondary phone markets continue to grow, and organizations like the GSMA and major carriers rely on IMEI-based databases to blacklist stolen devices and keep fraud down.

Used thoughtfully, these 14 codes turn your phone into a diagnostic kit and give you more control over how calls and alerts behave. Just remember the golden rule: verify the code, know what it does, and back up before you try anything that changes system settings.

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