Theoretically we can use a standardized 7% for all input and output tax transactions. However in the GST Form 5 reporting, you are required to report separately, either sales sales or purchase and within the sales to split into Standard rated, Zero-Rated or Exempt Supplies. Therefor the standardized 7% common rate does not work well in this aspect.
Example of the GST table and box numbers are:-
The result is user will have to select from the list as follow:-