IRAS had been implement Customer Accounting on GST with introduced of new tax codes.
Refer to [Guide on Accounting Software (for Software Developers)_V1.0_Oct 2017.pdf], look for keyword 'Customer Accounting'
Refer to Page 10 about Customer Accounting Supply
Refer to Page 15 for the affected area after implement of Customer Accounting
Refer to Page 18 for Customer Accounting on Types of Supplies part
Refer to Page 19 for Customer Accounting of New Tax Codes (SRCA-S, and SRCA-C)
Refer to Page 22 for Customer Accounting on Types of Purchases part
Refer to Page 22 for Customer Accounting of New Tax Codes (TXCA)
Refer to Page 33 for Customer Accounting that affect GST-F5 Return (Box 1 and 5)
Refer to Page 33 for Customer Accounting that affect GST-F5 Return (Box 6 and 7)
