Incoming text message charged as outgoing when abroad

[Jonam]

Has anyone else come across being charged for an outgoing text message when receiving an incoming text message when roaming outside the EU?
I’ve had this on two occasions (Japan and USA) where O2 have charged me an outgoing text for an incoming text.
They’ve refunded me each time, but insist that their billing system is infallible and I must have sent a text.
Anyone else seen this?

[jonsie]

Never had a problem myself in either Japan or the US. If the charges are the exact times as the incoming texts then it shows something untoward is happening. Ask O2 to investigate even if they have refunded the charges. Incidentally, how much were the charges?

[MI5]

@Jonam 

It can also depend on the phone.

An iPhone,for example, will send a silent text to register on a new network for facetime and iMessage. If abroad and outside the EU, you would be charged for this.

[Jonam]

The times of the messages don’t match up precisely with the incoming texts (but the day and number seem to).y For instance in Japan I activated my O2 SIM once in the middle to check for any texts and got one from O2 telling me my bill was ready.
Checking my bill a few days later there was a charge for an outgoing text for 41p on that day.
In the USA it was two authentication texts and two outgoing text charges on that day.
It was using an iPhone , but a different iPhone in the two trips

[MI5]

@Jonam 

As the messages are handled by an international network there's no guarantee that the times are exact. 

It could be the time the foreign network billed O2 and not the time sent.