Talk:Netherlands/@comment-185.220.101.7-20180909000808/@comment-24682153-20180909064921

"Anfrage feelgeslagen" means request failed. Sometimes USSD codes don't work in roaming networks. But here it looks like this *100# code is not employed by T-Mobile NL for balance checks. Different operators use different codes and ways. According to the T-Mobile NL website you have these ways to check you balance:

https://www.t-mobile.nl/tegoed

Log in to My T-Mobile personal account, use the My T-Mobile app, text 'SALDO' to 1144 or call 1244. No mention of an USSD code.