Hello @Diana0705 ,
Welcome to the community,
Did you use the SIM card in the UK to make a chargeable call or text first? Recharging the SIM card does not enable roaming, as it first needs to be used in the UK.
Did you receive the welcome message once in Romania?
I take it you are on pay as you go and not a monthly contract, as monthly contracts would need roaming enabled on the account first.
If you did first use the SIM card in the UK, you could try rebooting the phone, you can also do a manual search of a network, by going to settings and then switching automatic network off and doing a manual search for a network.
To contact EE customer service dial 150 from your mobile phone or ring customer service for free using Skype or another phone: +44 800 079 8586 or +44 800 956 6000.
