| Advance | Money a customer paid that isn't set against an invoice yet. Applied later with Apply advance. See Advances. |
| Aging | What customers owe, grouped by how long it is past the due date: not yet due, 1–30, 31–60, 61–90 and over 90 days. |
| B2B / B2C | Sales to customers with a GSTIN (B2B) or without one (B2C). Used in the GSTR-1 reports. |
| Balance due | An invoice's total, less payments received, less credit notes. |
| Bill of Supply | An invoice without GST, issued by a business that has no GSTIN. |
| CGST, SGST, IGST | GST within your state is split into central (CGST) and state (SGST) halves. GST on sales to another state is charged as integrated GST (IGST) at the full rate. |
| Credit note | A document that reduces what a customer owes on a saved invoice, for a return or a price correction. |
| Draft | An invoice, estimate or expense that is still being prepared. It has no number, doesn't count as a sale and doesn't change stock. |
| Financial year | 1 April to 31 March. Biththi's date filters and reports follow it. |
| GSTIN | A business's 15-character GST registration number. Its first two digits are the state code. |
| HSN / SAC | Codes that classify goods (HSN) and services (SAC) for GST. |
| Input tax | GST you paid on purchases, which may be set against the GST you charge. |
| Net sales | Saved invoices, less credit notes, in a period. |
| Place of supply | The state where a sale is delivered. It decides whether an invoice charges CGST + SGST or IGST. |
| Primary admin | The organization's owner: the person who signed up, or whoever they handed ownership to. |
| Purchase bill | A bill for goods you bought, entered line by line. Adds product quantities to stock. |
| Reorder level | The stock quantity at which a product counts as low stock. |
| Round-off | The small amount added or taken off to bring an invoice total to a whole rupee. |
| Saved invoice | A final invoice. It has a number, counts as a sale, changes stock and can't be edited. |
| Statement of account | A customer's invoices, payments and credit notes over a period with a running balance. |
| Taxable value | A line's amount after discount and before GST. |
| Watermark | The small Biththi mark on Starter plan invoices and estimates. |
