Sales Tax and Account on a Voucher

Hello ,

I am posting this on behalf of my user who do not have access to this community.

1 ) How does Sales tax get populated on a voucher with PO and without PO.

2) How does account get populated on the Voucher.

3 ) How does the Sales Use Tax amount get charged to a particular Account.

Meaning how do you make sure the Sales Tax amount get charged toa particular account.

I am new to AP module, please excuse if my questions are unclear.

Thanks in advance