In Menu facility click on Orange logo
then Orange Plus
then Pay as you Go
which then sends short Txt to Orange
They will respond almost immediately with your Account Balance
Right if you are on pay as you go, the number from an orange phone is 453. if you are on a pay monthly contract the number is 150 from an orange phone.
if you are not checking from an orange phone you can call 07973100 150 (pay monthly) or 07973100 453(payg)
hope this helps you