How to Fix DTMF Tone Issue in iOS 8 Devices


Lot of users reported about this problem. They can dial into conference calls. But when they enter the code, conference bridge does not recognize the input (DTMF tones) – iPhone 6 (ios 8). But this problem not happened in iOS 7 devices like iPhone 5 with iOS 7.

So how to fix this issue?

According to Sprint customer service,

Step 1: First turn on the home Wi-Fi.

Step 2: Connect your iOS Device (iPhone, iPad) to the Wi-Fi .

Step 3: Move to a strong Wi-Fi connection zone.

Step 4: Tap you iPhone. Also Tap keypad if necessary.

Step 5: Dial  ##CLEAR# (##25327#)

Step 6: Tab call in your iPhone

Step 7: Press ok in  Resetting Subscriber settings prompt and allow the radio to reset.

If you find any other solution for this problem, do let us via comment.

Also read other iOS 8 issue related articles like “iPhone 6 slow Wi-Fi issue“, “No service and touch id issue in iOS 8.0.1” and “car Bluetooth connectivity issue in iPhone 6“.

4:06 pm

8 responses to How to Fix DTMF Tone Issue in iOS 8 Devices

The DMTF issues seems to be caused by using LTE Voice on the iPhone 6. I was able to resolve this issue by changing my LTE settings.

Go to: Settings->Cellular->Enable LTE->

Change the setting from Voice and Data to Data Only

Reboot your phone.

Problem Solved!!

Thank you,

Michael Gardiner

I recently had this problem on my iPhone6 with my bank and my credit card company. My software version is current (IOS 9.0.2). I'm right next to my router and have a strong wifi signal. If the phone is making wifi calls, the tones weren't recognized, but if I was only connected to my carrier (T-Mobile) the tones worked. Then, I noticed that I had turned the setting on for my phone to function as a wi-fi hotspot. Once I toggled this to off, the tones worked even when the phone was on wifi. I tried toggling the hotspot off and on several times, and the tones always failed when it was on, and always went through when it was off. I don't know if this is a quirk or a security feature. But I definitely recommend checking into your wifi and/or hotspot settings.

I checked all of the settings suggested above and tones are still not recognized by our business phone system. (Cannot dial and extension).

Any other suggestions?

Michael Gardiner's solution worked for me on my iPhone 6S Plus. I'd called Apple several times and the Level 2's to whom I spoke were clueless. One wanted me to to wipe and restore the phone but to call T Mobile first. I'd transferred to T-Mobile when I got this new phone on Sept 25th and didn't know whether the phone or T-Mobile was causing the problem. It is clearly a software issue on the settings on the iPhone. T-Moble asked me to wait three days for an answer from their tech team. My phone was not able to send a signal to several important phone numbers that won't take voice input only the numerical input, so I was paralyzed. But changing the LTE settings to Data Only and restarting the phone worked for me. Thank you Michael Gardiner.

Yesterday I said that the change from Voice and Data to Data Only solved the problem with the DTMF tones but it only solved it for one phone number. Today I spoke with a Tech Supv at T-Mobie and solved the whole problem. I had this problem with the new iPhone 6S Plus and at the same time I'd switched from AT&T to T-Mobile so troubleshooting was complex. The solution is that my phone was set to call using WiFi and my WiFi signal at home was sketchy, using an old Apple Time Capsule. It's very old. When I turned off WiFi calling my signal went from between 1-2 bars to between 2-4 bars and I was also able to call the remaining automated number that wasn't receiving my DTMF tones. So T-Mobile is sending me on loan for free a very powerful router they recently acquired. This router should boost my WiFi signal at home significantly. I don't usually call those automated phones when I am not at home. I also have a low signal in the stores I frequent, lower on T-Mobile than I had on AT&T, however, while they are checking on that issue, since I don't call automated numbers that require DTMF signals from those stores it doesn't pertain to this problem. Except the low signal seems relevant to the ability to send DTMF.

I've had the same problem. I noticed the post over and turned off my hotspot and i think that's what did it. I'm not on wifi though so i'm not sure if it's just the hotspot setting, wifi setiing or both. but either way that's what happened for me.

Leave a Reply