shortcode sms - per country or int'l?

Question as title - does anyone know if 5 figure sms numbers are
allocated to be used only in one country each, or can some messages be
sent internationally to other countries, or maybe to one's home country
while roaming?

andy wrote:

> Question as title - does anyone know if 5 figure sms numbers are
> allocated to be used only in one country each, or can some messages be
> sent internationally to other countries, or maybe to one's home country
> while roaming?
>
When using my Orange PAYG in the US, the 'welcome' message from Cingular
said that short codes could be used as if back in the UK. I haven't
tried it, though - I just leave the phone on to _receive_ texts, and use
a US phone to respond (cheaper than roaming).