My sim doesn't work in austria

[Leejiho]

I bought it at Uk, it works in uk but it doesn't work in czech, austria.

[bristolian]

Is this a pay-monthly SIM, or a PAYG one?

PAYG phones are auto-enabled for roaming once they're used in the UK first.

Pay-monthly lines need to have roaming enabled manually - usually by texting ROAMING to 150 before leaving the UK.