to ask if a phone ringing once and going to voicemail

[User300400]

Definitely means you are blocked or could the phone just be off?

If it’s off it goes straight to voicemail or the one ring could be call cancelled or signal drop off

As far I’m aware it will go to voicemail when switched off/no network reception or blocked.

Could be signal drop or they're busy and have sent the call to voice mail.

Is it on ee? My ds's phone does this and we don't know why, he doesn't press anything and it doesn't ring at his end

On an iPhone it rings once then goes to voicemail if your number is blocked.

Their phone might be on do not disturb

It depends on where you're calling from, at work on the landline it rings once to say your call has gone through, it then either bells in a different but v similar tone if it connects and the recipient's phone is ringing or goes to vm/ unavailable message if no vm set up. I think most mobile networks send you to the unavailable message rather than personal vm if they have one if you're blocked but I stand to be corrected on that.

My iPhone is doing this today and have no idea why no one can call me

This normally happens when the call is redirected (e.g. on do not disturb mode)

My partners phone does this when he has it on do not disturb mode (iPhone on 3). If you call twice immediately in a row you get through the second time though.

My phone doesn't this when I already have a voicemail I haven't listened to.

My DDs phone was doing this last year, we googled it and found that she had it on Do not disturb from being at college.

Like Cwenthryth she also got the call on the second attempt. I can’t remember why that is, but something like the first call ‘unlocks’ the phone meaning that the second attempt rings the phone.

Sometimes it happens if the person you’re calling has bad signal too

If iPhone as others have said do not disturb autoroutes to voicemail. I use it during meetings or when busy for long periods.

So it could mean the phone simply has no battery or is off?

Nope, my dads phone does this all the time. He’s on Vodafone, no rhyme or reason to it but it sometimes rings once and cuts off.
Or as PP said, iPhones Do Not Disturb setting does this I think.