How does SMS work if people are roaming or texting non (their country) numbers?
There are several possible cases to consider, assumed as based on the UK and ‘nonUK’ as an example:
- (either you are sending to UK people and some of them are roaming on holiday, or you are sending to a non-UK list and there are some UK numbers in it
- Anytime you send to a UK mobile, Dynmark delivers to their UK Network. The network knows they are roaming and forwards the message onwards.
- The Network pay to forward it, the cost to you is no different to them being in UK (so what matters is the country of origin of mobiles not the country they are in when texted)
- The message should be forwarded like a P2P message, normally with originator intact but this cannot be guaranteed since it depends on the roaming network and agreement
iii. There is an exception to this for USA
- Messages sent to UK mobiles with a US long number originator are not delivered since they are routed on a US long number only delivery network
- Someone is roaming and wants to reply / text a number
- They text a number in the country they are in:
- Local long code – gets forwarded but the reliability depends on the quality of the connection for the number
- Local shortcode – unlikely to get forwarded
- UK long code – will get forwarded with high reliability since UK long numbers are very well connected
- UK shortcode – should get forwarded but not trusted as 100%
- 3rd party country long code - gets forwarded but the reliability depends on the quality of the connection for the number
- NOTE: They will always pay the roaming text fee, whatever country they text (typically 50p at present).
iii. NOTE: The message will be delivered by their HOME network not their roaming partner so if sent to a number in the roaming country the message will be delivered via home
- Someone has a UK mobile and is asked to text outside UK
- If they are texting a UK mobile anywhere they are not charged extra
If the mobile is non UK, they pay an international texting charge, typically 20-24p for example but it depends on the network