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Discounts: application logic

In the system, a discount is a separate “Discount” object that can be applied to sales document lines (primarily, to sales order lines).

A discount can be defined:

  • as a discount percent;
  • as a price from a price type (that is, “fix the price by another price type”).

Where discounts are configured​

Usually, the discount list is located in “Sales” → “Operations” → “Discounts”.

In the discount card, you specify:

  • validity period;
  • applicability conditions;
  • which items/categories it applies to;
  • which price types are allowed;
  • if needed — which warehouses/locations it applies to;
  • discount amount (percent) or a price type (if the discount is defined by price).

How the system decides whether a discount matches a line​

For a sales order line, the system checks a discount against a set of conditions.

1) By items and categories​

A discount can be linked:

  • to specific items;
  • to item categories (category hierarchy).

If neither categories nor items are selected in a discount, the discount is considered misconfigured and the system will not allow saving it.

2) By validity period​

A discount is applied only if the line date is within the interval:

  • the line date is not earlier than the start date;
  • the line date is not later than the end date.

3) By price type​

A discount can be restricted by price types:

  • if price types are specified in the discount, it applies only to lines with one of these price types;
  • if price types are not specified, the restriction does not apply.

4) By warehouse/location​

A discount can be restricted by warehouses/locations:

  • if warehouses/locations are specified in the discount, it applies only to lines with a matching warehouse/location;
  • if warehouses/locations are not specified, the restriction does not apply.

5) By minimum quantity and line amount​

A discount can require that the line has at least:

  • a minimum quantity;
  • a minimum amount.

If the line does not reach the threshold, the discount is not applied.

Important: the amount used for the check is the “full amount” (calculated from quantity and price; tax may be included if applicable).

6) By cumulative conditions per customer​

A discount can be cumulative and enabled only if the customer has:

  • total volume of previous purchases above a threshold;
  • or purchase volume for the previous month above a threshold.

These values are taken from the customer’s sales history.

How the price is calculated for a discount​

For each matching discount, the system calculates the “discount price”.

Option 1: percent discount​

If the discount specifies a percent, the discount price is calculated as:

discount price = base price × (100 − discount percent) / 100

Option 2: discount via price type​

If the discount specifies a price type, the discount price is taken from this price type for the line date.

Practical meaning:

  • you can define a discount as “sell at wholesale price” or “sell at the price from a special price list”.

How an automatic discount is selected​

If multiple discounts match a line, the system automatically selects the most beneficial for the customer among automatic discounts.

Selection rule:

  • among all matching automatic discounts, the one with the minimum discount price is selected.

This corresponds to the selection logic in code: the discount with the minimal calculated price is chosen.

Important:

  • discounts are not summed;
  • one discount is chosen that gives the minimum price (that is, the “best benefit” within the configured discounts).

Manual discount selection in a line​

In a sales order line, a user can manually select a discount (the “Discount” field).

How it works:

  1. The user opens the discount selection.
  2. The system shows only discounts that match the line by conditions.
  3. The user selects a discount.

If the selected discount is percent-based, the system fills in the percent in the line (if the user has not entered a percent manually).

If the selected discount is defined by a price type, the system fills in the price by that price type and recalculates the discount/line amount.

Automatic discount recalculation​

If automatic discount recalculation is enabled, the system recalculates the discount for a line when these values change:

  • document/line date;
  • customer;
  • item;
  • quantity;
  • price;
  • document type;
  • warehouse/location;
  • total document amount.

Automatic recalculation is performed only for discounts that are not marked as “manual”.

The order also has the “Calculate discounts” action, which forces recalculation of discounts for all lines (except manual ones).

How to disable auto recalculation​

In settings, there is a parameter “Do not automatically calculate discounts in order”.

If it is enabled:

  • automatic recalculation on changes is not performed;
  • the user applies discounts manually and/or via the “Calculate discounts” button.

Where discounts are shown​

Discounts are usually visible:

  • in order lines (selected discount, percent/price);
  • in order totals (discount amount for the document);
  • in invoices (if discounts are transferred to the invoice);
  • in sales reports.

Typical issues​

  • Discount is not applied — check date, price type, warehouse/location, quantity/amount thresholds, and item/category restrictions.
  • Multiple discounts match but a “wrong” one is selected — the system selects the discount with the minimum discount price. If you need another one, use manual selection.
  • Discount “disappears” after changing a line — auto recalculation is enabled and the selected discount is not manual.

Examples​

Below are a few simplified examples to illustrate how the rules work.

Example 1. Percent discount with a quantity threshold​

Discount conditions:

  • items: “Cable” (or category “Cables”);
  • validity: current month;
  • minimum quantity in line: 10;
  • discount: 5%.

Order situation:

  • line: “Cable”, quantity 8, price 100.

Result:

  • the discount is not applied, because the quantity is less than 10.

If you change the quantity to 10:

  • discount price = 100 × (100 − 5) / 100 = 95;
  • the line will use price 95 (or percent 5%, depending on how your form is configured to display it).

Example 2. Discount via a price type​

Discount conditions:

  • items: category “Home appliances”;
  • discount is defined via price type: “Wholesale”;
  • validity: unlimited.

Order situation:

  • line: “Kettle”, quantity 1;
  • current order price (for example, by a base price type) — 3,000;
  • price by the “Wholesale” price type on the order date — 2,700.

Result:

  • when applying this discount, the system will fill in price 2,700.

Practical meaning: instead of calculating a “percent”, you fix that prices from another price type should be used for this group of goods.

Example 3. Two discounts match — the most beneficial one is selected​

Let two automatic discounts match a line:

  1. Discount A: 10%
  2. Discount B: 5%

Base price in the line: 100.

Discount price:

  • for discount A: 100 × (100 − 10) / 100 = 90;
  • for discount B: 100 × (100 − 5) / 100 = 95.

Auto selection:

  • the system will select discount A, because the discount price 90 is lower than 95.

If business rules require applying another discount (not the most beneficial one), use manual discount selection in the line.