Purchase

Edit Purchase Line Quantity, Cost and Tax

Quantity, cost and tax edits recalculate the purchase immediately. A cost edit also updates the item's stored company price through a separate request; a tax edit changes the current purchase line but does not update the item tax master.

Menu path
Purchase -> Purchases -> New Purchase or open purchase -> Edit
Verified from
Posnic demo and current POS source reviewed on 2026-09-08
Technical source evidence

frontend/modules/receivings_write.html receiving item table and totals, frontend/static/script/js/modules/js/receiving_add.js editItemCompanyPriceReceiving, frontend/static/script/js/modules/js/receiving_add.js editItemTaxReceiving, frontend/static/script/js/modules/js/receiving_add.js receivingTextboxQtyChange and addLineReceivingChangeQty, frontend/static/script/js/modules/js/receiving_add.js removeLineItemReceiving confirmation

Purchase line controlsAdd the correct supplier item, then review quantity, unit, cost, exclusive tax and line total before saving.
Verify an edited purchaseAfter every line correction, compare subtotal, tax, charges and grand total with the supplier document.

Know What Each Line Control Changes

ControlImmediate resultPersistence warning
QuantityRecalculates line value, line tax, subtotal and grand total.Saved with the purchase and used for stock movement when received.
Cost edit iconAccepts a non-negative decimal, shows two decimals and recalculates the line.Also sends a separate company-price update for the item; future workflows can see the new stored cost.
Exclusive Tax edit iconChanges the visible percentage and recalculates this purchase line.Does not update the item's tax master; correct the item separately when its standard tax is wrong.
Pack conversionMultiplies the entered pack count by the item's conversion factor.The resulting base-unit quantity is what the receiving calculation uses.
Remove lineRemoves the line after confirmation and recalculates totals.No quantity from that line enters this purchase when saved.

Correct a Line Before Saving

  1. Select the supplier first, then add or scan the intended item.
  2. Compare item name and unit with the supplier invoice or delivery note.
  3. Enter the received or ordered quantity in the Qty field.
  4. If the supplier unit cost differs, select the edit icon beside Cost and enter the approved decimal amount.
  5. When Exclusive Tax is enabled and the invoice rate differs, select the tax edit icon and enter a value from 0 to 100.
  6. Check the line Total after each change instead of editing several fields blindly.
  7. Compare subtotal, tax, additional charges and grand total with the supplier document.
  8. Save once, reopen the purchase and confirm the stored line and stock result.

Understand the Calculation

Tax stateLine calculationOperator check
Exclusive Tax selected and line is exclusiveQuantity x cost, plus that base multiplied by the line tax percentage.Supplier cost must be before tax.
Exclusive Tax clearedThe current flow sets the line's added exclusive tax to zero.Do not assume Posnic extracts included tax from the entered cost.
Quantity changedThe same cost and active tax treatment are recalculated for the new quantity.Check decimal quantities and the displayed unit.
Additional charges presentCharges are added at document level after line calculations.They do not change item cost or line tax.
Total rounding enabledDisplayed grand total can be rounded while the underlying computed total is retained.Reconcile the supplier invoice and rounding policy.

Cost Edit Has a Wider Effect

The Cost edit is not only a temporary visual correction. After accepting it, Posnic calls the company-price update endpoint for that item independently of the later purchase Save action.

  • Use the cost edit only when the new item cost is approved.
  • Do not experiment with a cost value and expect Close or Clear to undo the item-master update.
  • If the purchase needs a one-off document value but the catalog cost must remain unchanged, follow the owner's approved costing policy before editing.
  • After an accidental cost edit, open the item record, verify Company Price and correct it with authorization.
  • Review margin and selling-price decisions separately; changing purchase cost does not automatically prove the selling price is still suitable.

Tax Edit Is Purchase-Specific

  • The tax edit appears with the Exclusive Tax column and accepts decimal values between 0 and 100.
  • It recalculates the current line and marks the line as exclusive for the receiving calculation.
  • It does not rewrite the item's configured tax rate or tax type.
  • If the supplier invoice exposes a catalog tax setup error, finish the controlled purchase correction and then fix the item tax master separately.
  • Changing today's item master does not recompute historical purchase documents.

Returns and Existing Purchases

SituationCurrent guardCorrect response
Supplier return quantityPosnic limits the entered return to the available purchased quantity and warns when exceeded.Return only the quantity actually sent back.
Partially received orderStatus and remaining receiving belong to the Receive workflow.Receive or close the remaining quantity from the purchase document.
Remove existing lineA confirmation modal appears before the row is removed.Confirm item identity and inventory consequence first.
Closed or controlled historyAvailable edit actions depend on state and permission.Use return, void or approved correction rather than rewriting evidence.
Decimal quantityQuantity calculation supports decimals and step controls can move by 0.01.Use only when the item's unit genuinely supports fractional stock.

Troubleshooting

ProblemLikely reasonControlled response
Cost edit says Enter a valid amountValue is blank, negative or not a valid decimal.Enter a non-negative number using a decimal point.
Tax column is hiddenExclusive Tax is cleared.Verify invoice tax treatment before enabling it; do not enable only to expose the editor.
Tax returns to the old rate on another purchaseLine tax edit did not update the item tax master.Correct the item's standard tax assignment with approval.
Future purchases show an unexpected costA previous receiving cost edit updated Company Price.Audit the item record and the purchase that introduced the change.
Total differs from invoiceQuantity, cost, tax, charges or tax-mode interpretation differs.Reconcile each component and use the invoice-total warning as a review signal.
Return quantity is reduced automaticallyRequested return exceeded available quantity.Verify prior returns and return only remaining eligible stock.
Removed line disappearedRemoval was confirmed.Re-add the correct item before save; after save use the approved correction workflow.

Manager Verification Checklist

  • Supplier, item and unit match the external document.
  • Quantity reflects ordered, received or returned stock correctly.
  • Any cost override is approved and its item-master effect is understood.
  • Any line tax override is supported and the item master is corrected separately when required.
  • Line totals, subtotal, tax, charges and grand total reconcile.
  • Saved purchase and inventory log show the intended result.
  • Unexpected company-price changes are reviewed before the next sale or purchase.

Related Manual Pages

Purchase Receive Stock Receiving is the point where purchased goods become trusted stock. The operator must match supplier, quantity, cost, invoice total, tax and proof before saving. Purchase Edit a Purchase Editing changes the original purchase. On received documents, tracked stock moves only by the difference between the old and new lines; partial receipts preserve quantities already accepted and must still be completed through Receive. Purchase Receive Packs as Units Posnic always stores received stock in the item's base unit. For configured items, the receiving row offers an explicit xN purchase-unit button that multiplies the entered pack count once and recalculates the line. Purchase Invoice Total Mismatch Posnic compares the supplier's declared tax-inclusive invoice total with its calculated purchase total. A difference above 0.50 is saved as a visible warning instead of blocking received stock. Purchase Freight and Charges Additional purchase charges increase the purchase grand total. They remain separate from item unit cost and tax so operators can reconcile supplier paperwork without distorting stock lines. Catalog Assign Item Tax Each taxed item stores its selected tax, tax method and whether the selling price includes tax or receives tax on top. Catalog Edit Existing Item Item edits affect future searches, scans, sales and reports immediately. Review the whole record, use a counted quantity, and test the result before serving customers. Inventory Inventory Logs Inventory Logs are the branch stock ledger. Each row opens a movement detail beside the list, where operators can inspect the reference and follow controlled links to the item, sale or purchase.