# #21# on iPhone: Pause Call Forwarding URL: https://byshahid.com/blog/pause-call-forwarding-hash-21-iphone/ App: Secret Codes: IMEI & Carrier (https://apps.apple.com/us/app/secret-codes-imei-carrier/id6807154322) Author: Muhammad Shahid Updated: 2026-11-04 > #21#: Switch forwarding off but keep the number saved. Deactivates unconditional forwarding while leaving the destination number registered with the network. Dial *21# later to switch it straight back on without re-entering the number. - **Code:** #21# - **What it does:** Switch forwarding off but keep the number saved. - **Published for:** AT&T and T-Mobile - **Type:** GSM networks Switch forwarding off but keep the number saved. This page explains what `#21#` does, how to use it on an iPhone and which carriers it applies to. I build **Secret Codes: IMEI & Carrier**, a free iPhone app with 317 checked codes and guides, including this one. If you would rather tap than memorise, [get Secret Codes on the App Store](https://apps.apple.com/us/app/secret-codes-imei-carrier/id6807154322). ## What does #21# do? Deactivates unconditional forwarding while leaving the destination number registered with the network. Dial [*21#](/blog/resume-call-forwarding-star-21-iphone/) later to switch it straight back on without re-entering the number. ## How do I use #21#? - Open the Phone app and tap Keypad. - Type #21# exactly as written. - Press the green Call button and wait for the result. ## Which carriers does this apply to? | Published for | AT&T and T-Mobile | | Type | GSM networks | | Good to know | GSM networks only. Some networks treat this the same as ##21# and clear the number anyway. | _Screenshot: The Secret Codes detail screen shows the steps, the carriers and an Open in Phone button._ ## Related call forwarding codes - [##21#: Turn Off Call Forwarding](/blog/turn-off-call-forwarding-hash-hash-21-iphone/) - [*21#: Resume Call Forwarding](/blog/resume-call-forwarding-star-21-iphone/) - [**21*[number]#: Turn On Call Forwarding](/blog/turn-on-call-forwarding-star-star-21-star-number-iphone/) - [*#61#: Check No-Answer Forwarding](/blog/check-no-answer-forwarding-star-hash-61-iphone/) - [*#21#: Check Call Forwarding Status](/blog/what-does-star-hash-21-mean/) - [**61*[number]#: Forward When You Don't Answer](/blog/forward-when-you-dont-answer-star-star-61-star-number-iphone/) See all [call forwarding codes](/blog/iphone-codes/call-forwarding/) or [every category of iPhone codes](/blog/iphone-codes/). ## How Secret Codes helps Secret Codes keeps this and every other entry a search away. Pick your carrier once and each entry says whether it is published for your line. You can save favourites, add a private note, and record whether a code worked on your line. This entry is part of Secret Codes Pro. **Secret Codes: IMEI & Carrier** is free on the App Store: https://apps.apple.com/us/app/secret-codes-imei-carrier/id6807154322 ## FAQ ### What does #21# do on iPhone? Switch forwarding off but keep the number saved. Deactivates unconditional forwarding while leaving the destination number registered with the network. Dial *21# later to switch it straight back on without re-entering the number. ### What are the steps for #21#? 1. Open the Phone app and tap Keypad. 2. Type #21# exactly as written. 3. Press the green Call button and wait for the result. ### Where do I use #21#? On the keypad of the Phone app. ### Do I need to press Call after typing #21#? Yes. Type it on the Phone keypad, then press the green Call button. ### Is #21# a hidden or secret code? No. It is a standard GSM code, handled by the network rather than by a hidden menu on the iPhone. ### Which carriers does #21# work on? It is published for AT&T and T-Mobile. GSM networks only. Some networks treat this the same as ##21# and clear the number anyway. ### Does #21# work on Android phones too? GSM codes are a network standard, so they generally behave the same on any phone on a network that supports them. ### Will #21# work outside the US? It depends on the network you are on. GSM codes are a standard, but each network decides which it supports. ### What if #21# does not work on my iPhone? Check that it applies to your carrier first, because carriers decide which services they offer and can change them. If it should apply to your line, contact your carrier. ### What is related to #21#? ##21#: Turn Off Call Forwarding. Erase unconditional forwarding completely. ### What else is in this category? *21#: Resume Call Forwarding. Re-enable forwarding using the number already stored. ### Can I find #21# in an app? Yes. Secret Codes, a free iPhone app, includes it with its steps and carrier details, as part of Secret Codes Pro. ## Sources - [3GPP TS 22.030: Man-Machine Interface of the phone](https://www.3gpp.org/dynareport/22030.htm) - [Verizon Support](https://www.verizon.com/support/)