Discount reminder

One day after an incoming invoice is approved, the script checks whether its early-payment discount still applies. While the period runs, it reminds accounting of the last day to pay and the amount saved, and tags the invoice “Skonto”. The discount period and rate are fields the workflow adds itself. With a card it needs no script: Watch the Skonto deadline reads the Skonto terms and gives the approval the Skonto date as its deadline.

The workflow

The workflow starts for every document of the type incoming-invoice. Its file workflow.yaml:

$schema: 'https://docs.acriva.de/schemas/workflow.schema.json'
format: 1
schemaVersion: 4
sdk: '1.0.0'
key: skonto-reminder
name: Skonto-Erinnerung
template: custom
trigger:
  documentType: incoming-invoice
fields:
  - key: discountDays
    kind: number
    labelDe: Skontofrist (Tage)
    labelEn: Discount period (days)
    documentTypes:
      - incoming-invoice
  - key: discountPercent
    kind: number
    labelDe: Skonto (%)
    labelEn: Discount (%)
    documentTypes:
      - incoming-invoice
start: approve
steps:
  - kind: humanTask
    name: approve
    label: Freigabe
    taskKind: approve
    assignees:
      - when: null
        assignee:
          kind: costCenterResponsible
    fallback:
      kind: role
      role: Buchhaltung
    options:
      excludeRequester: true
      excludeActorsOfSteps: []
      pickFile: false
    next: wait
    onRejected: rejected
  - kind: timer
    name: wait
    label: Einen Tag warten
    days: 1
    daysBefore: 0
    next: remind
  - kind: script
    name: remind
    label: An Skonto erinnern
    script: remind.ts
    hook: onTimer
    inputs:
      - kind: field
        key: invoiceNumber
        type: text
      - kind: field
        key: invoiceDate
        type: date
      - kind: field
        key: totalGross
        type: money
      - kind: field
        key: discountDays
        type: number
      - kind: field
        key: discountPercent
        type: number
    returns: []
    exits: []
    next: approved
  - kind: end
    name: approved
    label: Freigegeben
    outcome: approved
  - kind: end
    name: rejected
    label: Zurückgewiesen
    outcome: rejected

The script remind.ts

Hook: onTimer · Inputs: invoiceNumber, invoiceDate, totalGross, discountDays, discountPercent · Return values: none

import { date, defineScript, money } from '@acriva/workflow-sdk';

export default defineScript({
  hook: 'onTimer',
  run(ctx) {
    const { invoiceNumber, invoiceDate, totalGross, discountDays, discountPercent } =
      ctx.document.fields;
    // Without the invoice date, the discount period or the discount there is nothing to remind of.
    if (invoiceDate == null || discountDays == null || discountPercent == null) return;

    // The discount applies up to and including the last day of its period, counted in whole days.
    const deadline = date.addDays(invoiceDate, Math.trunc(discountDays));
    if (ctx.today() > deadline) {
      ctx.log('Discount expired on', date.format(deadline));
      return;
    }

    const percent = String(discountPercent).replace('.', ',');
    const saving =
      totalGross == null
        ? ''
        : ` Das sind ${money.format(money.round((totalGross * discountPercent) / 100))}.`;
    ctx.notify({
      to: [{ role: 'Buchhaltung' }],
      text:
        `Die Rechnung ${invoiceNumber ?? 'ohne Nummer'} ist freigegeben. ` +
        `Bei Zahlung bis ${date.format(deadline)} ziehen Sie ${percent} % Skonto ab.${saving}`,
    });
    ctx.addTag('Skonto');
  },
});

What it does

A test runs each of these cases in the sandbox and compares the result.

The discount still applies

• Input: invoiceNumber RE-2026-0815, invoiceDate 2026-10-15, totalGross 1190, discountDays 14, discountPercent 2, last task outcome Approved, today 2026-10-22
• Exit: the default next step
• Changes: notification to the role Buchhaltung: “Die Rechnung RE-2026-0815 ist freigegeben. Bei Zahlung bis 29.10.2026 ziehen Sie 2 % Skonto ab. Das sind 23,80 €.”; tag “Skonto”

The discount period has ended

• Input: invoiceNumber RE-2026-0702, invoiceDate 2026-10-01, totalGross 499.8, discountDays 10, discountPercent 3, last task outcome Approved, today 2026-10-22
• Exit: the default next step
• Changes: none

An invoice without a discount

• Input: invoiceNumber RE-2026-0911, invoiceDate 2026-10-20, totalGross 250, discountDays null, discountPercent null, last task outcome Approved
• Exit: the default next step
• Changes: none