iPhone Secret Codes & 5G/LTE Field Test Mode (dBm) Explorer (2026)

Viral social media posts often claim that seeing a phone number under `*#61#` (When Unanswered), `*#62#` (When Unreachable), or `*#67#` (When Busy) proves your phone is tapped. In reality, mobile carriers use Conditional Call Forwarding by default to route unanswered or busy calls to your carrier's official Voicemail Deposit Center number. Only unconditional forwarding (`*#21#` active for all calls) or forwarding to an unrecognized personal phone number indicates tampering.

RSRP (Reference Signal Received Power) is measured in negative decibel-milliwatts (dBm) on a logarithmic scale where every 3 dB increase doubles the signal power: `-44 to -79 dBm` is Excellent (near the cell site), `-80 to -90 dBm` is Good, `-91 to -105 dBm` is Fair, and `-110 dBm or lower` is a cell edge dead-zone. SINR (Signal-to-Interference-plus-Noise Ratio) measures signal clarity: above `+20 dB` enables peak 5G 256-QAM speeds, while below `0 dB` indicates heavy interference.

Dialing `##002#` and pressing Call sends a standard 3GPP GSM/LTE/5G Supplementary Service deactivation command to your carrier's core network, immediately erasing all unconditional (`21`) and conditional (`61`, `62`, `67`) call forwarding rules on your line.

Codes processed locally by iOS firmware (such as `*#06#` to display hardware IMEI/EID barcodes) trigger the moment the final `#` is typed. Codes that query or modify network-side settings on your carrier's HLR/HSS switch (such as `*3001#12345#*`, `*#21#`, or `##002#`) require pressing the green Call button to transmit the MMI/USSD request over the air.

In North America (NANP carriers like AT&T, Verizon, and T-Mobile), dial `*67` followed immediately by the 10-digit phone number (e.g., `*672125550199`). In Europe, the UK, India, and Australia (GSM standard), prefix the number with `#31#` (e.g., `#31#07700900077`).