Compare to records in to tables get only difference in other table

I've looked through all the related questions, but none of them does exactly what I need. I have two identically-structured tables (id, VoucherNbr, BalanceInit) - one is from our current production system (tableA), and the other is from a client's legacy system (tableB). Table A has records a,b,c,d,e (for example), and table B has a,b,c,d,e,f,g. Table B will always have all the values that exist in table A, but also has extra rows. I need to return a resultset that contains all the rows in table B that don't exist in table A (f and g, using the example.) How can I do this?
TABLE_1
ID | VoucherNbr         | BalanceInit
=============================================
1  | 1111111111111111   | 25.00
TABLE_2
ID | VoucherNbr         | BalanceInit
=============================================
2  | 1111111111111111   | 3.00
Expected output 
ID   | BalanceInit
=============================================
2    | 3.00

I've looked through all the related questions, but none of them does exactly what I need. I have two identically-structured tables (id, VoucherNbr, BalanceInit) - one is from our current production system (tableA), and the other is from a client's legacy system (tableB). Table A has records a,b,c,d,e (for example), and table B has a,b,c,d,e,f,g. Table B will always have all the values that exist in table A, but also has extra rows. I need to return a resultset that contains all the rows in table B that don't exist in table A (f and g, using the example.) How can I do this?

Ranjith@Learner @Microsoft products