Two money-housekeeping reports live alongside the Sales report (Reports › Sales): Open Invoices (who owes you) and Taxes & Shipping (what you collected, for filing).
Open Invoices
Outstanding balance, open and overdue counts, and collections in the last 30 days, with an aging view (current, 1–30, 31–60, 61–90, 90+ days past due) and the full list of open and partially paid invoices. You can record a payment against an invoice straight from the report, and export the list to CSV.
Taxes & Shipping
Pick a year and get the month-by-month sales tax and shipping you collected, with quarterly subtotals for filing. It combines website orders with POS and invoice sales; VAT charged at checkout is included, and state retail delivery fees appear in their own column when present. Marketplace sales are out of scope by design, since the venues collect and remit their own tax.
A note on timing: invoice sales count from the invoice date (most states want sales tax remitted on what has been invoiced, not just what has been paid). The Open Invoices report is where the not-yet-paid side stays visible.