Please help an oldie but goodie!!! going to USA

[amici-pat]

My once in a life time trip is only 3 months away and i need help.   I am not techie and find sending a text difficult, so you are really going to have to treat me like an idiot, well almost !!

I have an i phone 6 on pay as you go monthly  O2 and A Samsung Edge 7 on Contract.(Tesco).

I will not required Data except whilst in my vacation home which has good wi-fi, so I know to turn roaming off.

I have read everything I can about this and am still at a loss.   Having been in the US for a short time a couple of years' ago, I got into a terrible mess when trying to make calls., so here goes - 

There will be 2 UK Mobiles in USA so firstly what do I dial to reach the other mobile which will be in US at the same time - some say just dial as normal, and others say I need to add 011

Also, what will this cost me per minute and will it come out of my minutes or be added as an extra charge.

Secondly, calling back to UK from US - what do I dial and what will it cost (as above).

I have Tu, as suggested, on my O2 phone, but cannot get the hang of it, and can I get it on Tesco Mobile.

That will do for now, your help would be greatly appreciated

[Anonymous]

You'd call +44 then the mobile number tu works by using wifi or. Mobile. Network data

[MI5 · Accepted solution]

Call charges can be found using this checking tool here http://international.o2.co.uk/internationaltariffs/travelling_abroad
To call UK number it's 0044 and to call a USA number it's 001. Drop the first 0 in both cases.
Also turn off data completely on both phones and just leave wifi on to avoid the risk of data use. Just having roaming off doesn't always work.

[Cleoriff]

Also remember to turn voicemail Off before you travel by dialling 1760. (to turn it back on when you get home is 1750 )

When ringing back to the UK it's easier if you have those you are calling  already stored in your contacts list

A picture of charges shown in the list above is here..

[amici-pat]

Thank you for help, still unsure on the UK mobile to UK mobile whilst both in the US, would that be classed as calling UK, or calling US and as such do I need to dial a prefix, and if so which.

Sorry to be so 'needy' but I just can't wrap my head around this

[jonsie]

Calling a UK mobile in the US just dial the number, no prefix needed. 

[MI5]

Just call from Tugo and it will be free to call another uk mobile.