I have an iPhone5S running iOS 12.5.4.

Recently I have been getting annoying calls from my "ISP" threatening cut off my internet. I would block these, but they use a different number each time (often not even a valid number).

I would like to be able to refuse calls from suspicious looking unknown callers until they give up, but only have a "Slide to Answer" button. An Apple help site suggested double tap to cancel, but this doesn't work.

Thanks to those who answered. Unfortunately I have been unable to test, as the nuisance caller has stopped. (I mainly use the iPhone for outgoing calls, and only get calls from family or a few trusted contacts.)

  • 2
    Wasn't it one push on the power button for decline call?
    – Solar Mike
    Commented Jul 29, 2021 at 6:33
  • Can you add a screenshot?
    – nohillside
    Commented Jul 29, 2021 at 6:44
  • And I assume that you are aware of the possibility to silence/send to voicemail all unknown callers?
    – nohillside
    Commented Jul 29, 2021 at 6:52
  • I once accidentally did a recall on one of these (censored). iPhone started dialing a number different than shown. That tells me that AT&T is able to detect a forged caller ID and therefore ought to be blocking them!
    – WGroleau
    Commented Jul 29, 2021 at 6:54

2 Answers 2


Decline a call and send it directly to voicemail

Press the […] Sleep/Wake button […] twice quickly.



If your phone is locked, only slide to answer is present. You have to click the lock button once to silence, and twice to decline it. If it's unlocked, you can decline it normally.

More details here

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