Iff query

sale bill shown in iff and tax has been paid.

but one invoice failed to show in that quarterly return
one bill, party name changed by mistake.

now the query is...
1) how to rectify the wrong GST number in GST 1 but correctly filed in iff.

2) how to include the omitted invoice now

3) in both the cases, can the receiver claim ITC as it was correctly shown in iff.

veteran please clarify and advise 😌