Provisional assessment

Sir,

        As per section 60 of GST Act, provisional assessment is allowed only under the situations where a taxable person is is not able to determine the value of supply or the rate of tax, then he can approach the  proper officer to allow him to pay tax on provisional basis.  You may also note that final assessment order has to be passed within 180 days (normally).  But I understand that you have missed some sales and did not pay tax on it during 2017-18. Hence, provisional assessment is not applicable to the situations mentioned by you.

However,for your query, I suggest the following two options:

1. If GSTR-9 is not filed, please include the missed our sales turn over and pay the tax through DRC-03

2. If GSTR-9 already filed, you may voluntarily pay the tax along with interest through DRC-03 and intimate to the jurisdictional tax officer in writing (SPEED POST) and keep the acknowledgement safely with copy of DRC-03. This will save you from penalty, when department finds this omission in future.