You want to know why your current CA Prepayment filing shows $0 due even though your company had sales that month.
The amount included in this prepayment is based on the sales tax collected for that month, minus any credits, not the sales total itself
When credits exceed sales (total sales tax for month is negative) the payment amount is $0
For sales with no tax due to being exempt or non-taxable, there is no tax collected, so the payment amount would be $0 unless taxable sales were also processed
This form is filed to remit payment for sales tax collected during a filing term, so there is a payment amount only if the sales tax collected in that month was positive
Note: Credits are processed as part of the quarterly filing (CA CDTFA 401, 401 A2, etc.) and will be processed follow standard credit process when the actual return form is filed