For the billing that involved GST, would it be a “must” to put the wording “Tax Invoice” on the bill ?
To claim full input tax credit one has to have a full tax invoice. Otherwise you follow the input tax claim of a simplified tax invoice.
For simplified tax invoice, a GST registered person who makes a supply to end consumer (not businesses), intends to exclude the following particulars pursuant to section 33(3)(a) of the GST Act 2014, may do so without making an application to the Director General :
(a) the word ‘tax invoice’ (regulation 22(a) GSTR);
(b) name and address of the recipient (regulation 22(e) GSTR)
(c) the total amount payable exclusive of tax.