# *#330# on iPhone: Check All Barring Services URL: https://byshahid.com/blog/check-all-barring-services-star-hash-330-iphone/ App: Secret Codes: IMEI & Carrier (https://apps.apple.com/us/app/secret-codes-imei-carrier/id6807154322) Author: Muhammad Shahid Updated: 2026-11-04 > *#330#: Interrogate every barring service at once. Interrogates the grouped all barring services identifier. Where it works the network answers with a list, one line per service and basic service group, showing which are active. This is the right first string to try when you want to know whether a line supports GSM barring at all. - **Code:** *#330# - **What it does:** Interrogate every barring service at once. - **Published for:** AT&T and T-Mobile - **Type:** Support varies Interrogate every barring service at once. This page explains what `*#330#` 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 *#330# do? Interrogates the grouped all barring services identifier. Where it works the network answers with a list, one line per service and basic service group, showing which are active. This is the right first string to try when you want to know whether a line supports GSM barring at all. One dial, no password, no risk, and a complete picture if the network answers. ## How do I use *#330#? - Open the Phone app and tap Keypad. - Type *#330# 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 | Support varies | | Good to know | Read only. Treat a clean error as the answer that your line has no GSM barring subscription, which is normal for AT&T and T-Mobile consumer plans. | _Screenshot: The Secret Codes detail screen shows the steps, the carriers and an Open in Phone button._ ## Related call barring and sim pin codes - [#330*0000#: Cancel All Call Barring](/blog/cancel-all-call-barring-hash-330-star-0000-iphone/) - [#333*0000#: Cancel All Outgoing Barring](/blog/cancel-all-outgoing-barring-hash-333-star-0000-iphone/) - [*#351#: Check Roaming Incoming Barring](/blog/check-roaming-incoming-barring-star-hash-351-iphone/) - [*#333#: Check All Outgoing Barring](/blog/check-all-outgoing-barring-star-hash-333-iphone/) - [#351*0000#: Cancel Roaming Incoming Barring](/blog/cancel-roaming-incoming-barring-hash-351-star-0000-iphone/) - [#353*0000#: Cancel All Incoming Barring](/blog/cancel-all-incoming-barring-hash-353-star-0000-iphone/) See all [call barring and sim pin codes](/blog/iphone-codes/call-barring-and-sim/) 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 *#330# do on iPhone? Interrogate every barring service at once. Interrogates the grouped all barring services identifier. Where it works the network answers with a list, one line per service and basic service group, showing which are active. ### What else should I know about *#330#? This is the right first string to try when you want to know whether a line supports GSM barring at all. One dial, no password, no risk, and a complete picture if the network answers. ### What are the steps for *#330#? 1. Open the Phone app and tap Keypad. 2. Type *#330# exactly as written. 3. Press the green Call button and wait for the result. ### Where do I use *#330#? On the keypad of the Phone app. ### Do I need to press Call after typing *#330#? Yes. Type it on the Phone keypad, then press the green Call button. ### Is *#330# a hidden or secret code? No. It is a published service, not a hidden menu. iPhones do not have Android-style engineering menus. ### Which carriers does *#330# work on? It is published for AT&T and T-Mobile. Read only. Treat a clean error as the answer that your line has no GSM barring subscription, which is normal for AT&T and T-Mobile consumer plans. ### Does *#330# work on Android phones too? It is handled by the carrier or service rather than the iPhone, so it is not tied to one phone brand. Check with your carrier. ### Will *#330# work outside the US? It is published for US carriers and services, so do not count on it abroad. Ask your carrier before you travel. ### What if *#330# 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 *#330#? #330*0000#: Cancel All Call Barring. Clear every barring service on the line in one command. ### What else is in this category? #333*0000#: Cancel All Outgoing Barring. Clear outgoing, international and except-home barring together. ## Sources - [3GPP TS 22.030: Man-Machine Interface of the phone](https://www.3gpp.org/dynareport/22030.htm)