Phone says 306MB -- O2 says 500MB. How can that be?

[bmarton]

Hi, O2 says I've used up my 500MB allowance for my billing period (from 2nd to 2nd of each month) whereas my phone says I've used 306MB from the 2nd December. I'd understand a few % difference but this is over 60% more. How can this be? Has anyone experienced similar? Could they measure what they send and my phone measure what it receives? It wouldn't seem very fair to me then.

[Anonymous]

Have you looked at the reading in your myo2? You should receive a text when you have used 80% of your data allowance. Then another when you have used all of it. 

[MI5 Level 94: Supreme]

Your phone should take into account up and down data too and you shouldn't be seeing that much of a difference.
I check mine each month and the two tally to within a few mb.
Which phone are you using?

[bmarton]

Hi, It's a CAT S30 (Android). I've got the 80% sms today at 18:13 and the "used up all" message at 19:38. Which is funny as the phone was 2 metre from the wifi router, logged in the wifi network during this entire time. :-) I've checked in myO2 but it's not very informative apart that the allowance is gone.

[MI5 Level 94: Supreme]

The problem with the way o2 report data is that it isn't instant so it doesn't necessarily mean it was used whilst sitting on your wifi.
Even so I'd give cs a call to question the discrepancy.

[Anonymous]

It usually updates around midnight the statistics 

[bmarton]

Thanks everyone, I discussed in the Live chat and learned that yesterday early morning the counter at O2 showed 337MB. I guess I'll see what the phone's counter does in a day or two, maybe it'll have a sharp jump up to 500.

[Anonymous]

Welcome to the forum @bmarton & hope it all sorts itself out for you 

[MI5 Level 94: Supreme]

You might want to check you don't have apps updating in the background when on mobile data too.

[bmarton]

I dropped in an O2 store today and was told that a faulty SIM can do tricks like that. Apparently the phone itself measures traffic on a SIM card and then submits the data to O2. It's curious how this data can differ from what the phone is actually telling me but this seems to have been my case. Anyway, I now have a new SIM and will also turn off mobile data near wifi; these should solve it.