Leges-heffingen (municipal fee calculation)

Automated calculation, invoicing and refunding of municipal fees (leges) on cases, grounded in Gemeentewet art. 229 and the VNG Modelverordening leges.

Entity model

All leges data is stored as OpenRegister objects in the Procest register. The schemas are declared in the modular fragment lib/Settings/register.d/30-leges.json (ADR-037 — the monolith procest_register.json is never edited).

legesTariefTabel  (verordening version per fiscal year)
  └─ legesTarief        (tariff line, coupled to a zaaktype)
       ├─ legesVariant  (sub-tariff selected on case attributes)
       └─ legesKorting   (discount/exemption, condition-driven)
legesBerekening   (concrete calculation per case, with audit trail)
  └─ legesRestitutie (refund decision)

Amounts are stored in eurocents (integers) throughout.

Calculation flow

1. Import — an admin imports a verordening from a decidesk raadsbesluit (LegesVerordingImportService). CSV and XLSX attachments are parsed natively (XLSX as a zipped XML set, XXE-safe). A concept legesTariefTabel plus its legesTarief rows are created, with a diff vs. the current table.
2. Approve — LegesVerordeningService::approve() flips concept → vastgesteld and closes the previous overlapping table (geldigTotEnMet).
3. Calculate — on case creation (LegesCaseCreatedListener) or on demand, LegesCaseCalculationService::calculateForCase():
   • resolves the vastgesteld table valid on the case reference date (peildatum = startDate, never a later verordening),
   • selects the legesTarief coupled to the case's caseType,
   • evaluates legesVariant conditions (LegesConditionEvaluator),
   • computes the base amount (vast / percentage / staffel / variant override),
   • applies legesKorting records (age / income / repeat-application), flagging pending_minima_check when an income-dependent exemption needs verification,
   • splits VAT and persists a legesBerekening with a human-readable berekeningsToelichting.
4. Invoice — LegesShillinqService::createInvoice() posts to the shillinq accounts-receivable API (gated by leges_shillinq_enabled config).
5. Refund — on withdrawal (LegesCaseWithdrawnListener) or on demand, LegesRestitutieService::createRestitutie() applies the phase staffel (100 % within term / 75 % in progress / 0 % after decision) and requests a credit invoice.

API

Method	Path	Auth
POST	/api/leges/import-verordening	admin
GET	/api/admin/leges/verordeningen	admin
PATCH	/api/admin/leges/verordeningen/{id}	admin
POST	/api/admin/leges/verordeningen/{id}/approve	admin
GET	/api/cases/{caseId}/leges	user (case-scoped)
POST	/api/cases/{caseId}/leges/calculate	user (case-scoped)
GET	/api/cases/{caseId}/leges/audit-trail	user (case-scoped)
POST	/api/cases/{caseId}/leges/refund	user (case-scoped)

Per-case endpoints are #[NoAdminRequired] and verify the caller can access the referenced case (via CaseSharingService::canUserAccessCase) before acting — IDOR-safe (ADR-005). The BSN is never logged raw and no secret is returned.

Frontend

• LegesBerekeningPanel — case-detail sidebar tab (registry key, manifest-v2).
• LegesVerordeningenAdmin — admin page (manifest fragment src/manifest.d/30-leges.json).
• Dialogs: LegesRefundDialog, LegesVerordeningImportDialog.

Configuration keys

leges_*_schema (auto-configured on import via SettingsService), leges_shillinq_enabled, leges_shillinq_source, leges_betalingstermijn_dagen.

Seed data

SeedLegesData repair step seeds an example "Legesverordening 2026 Gemeente Amsterdam" with paspoort, rijbewijs (+ spoed variant + 65-plus exemption), omgevingsvergunning (bouwsom staffel) and APV-evenement tariffs.