Tariff and Cost Section — Migration Guide

OCPP 2.1 introduces Local Cost Calculation as a second cost calculation model alongside the existing Central Cost Calculation. This is the single largest change in Section I and brings 6 new use case flows (I07–I12), 5 new message pairs, a rich structured tariff data model (TariffType), and a new payment settlement flow (NotifySettlement).

Change Overview at a Glance

In 2.0.1, the CSMS always calculates costs centrally and sends results to the Charging Station. In 2.1, the Charging Station can calculate costs locally using structured tariff data provided by the CSMS.

CSMS Impact

These flows are entirely new in OCPP 2.1 and do not exist in 2.0.1.

4.1 New Message Pairs

4.2 SetDefaultTariffRequest (New)

Installs a default tariff on the CS. Supports per-EVSE or global (evseId=0) installation.

{
  "evseId": 0,           // 0 = all EVSEs, >0 = specific EVSE
  "tariff": { /* TariffType */ }
}

Response statuses: Accepted, Rejected, TooManyElements, ConditionNotSupported, DuplicateTariffId

4.3 GetTariffsRequest (New)

Queries installed tariffs and their EVSE/driver assignments.

{ "evseId": 0 }  // 0 = all EVSEs

Response statuses: Accepted, Rejected, NoTariff

4.4 ClearTariffsRequest (New)

Removes default tariffs. Can target specific tariff IDs and/or specific EVSEs.

{
  "tariffIds": ["Default01"],  // Optional. Omit to clear all.
  "evseId": 1                  // Optional. Omit to clear from all EVSEs.
}

Response statuses per tariff: Accepted, Rejected, NoTariff

4.5 ChangeTransactionTariffRequest (New)

Changes the tariff for an active transaction. The currency must match the current tariff.

{
  "transactionId": "1234",
  "tariff": { /* TariffType */ }
}

Response statuses: Accepted, Rejected, TooManyElements, ConditionNotSupported, TxNotFound, NoCurrencyChange

4.6 NotifySettlementRequest (New)

Sent by the CS when a payment terminal completes a settlement.

{
  "pspRef": "PSP-123456",            // Payment reference
  "status": "Settled",               // Settled | Canceled | Rejected | Failed
  "settlementAmount": 15.75,
  "settlementTime": "2024-01-15T15:00:00Z",
  "transactionId": "tx-123",         // Optional
  "receiptId": "REC-001",            // Optional
  "receiptUrl": "https://...",        // Optional
  "vatCompany": { /* AddressType */ },// Optional
  "vatNumber": "NL123456789B01"       // Optional
}

Response (optional fields): receiptUrl, receiptId

5.1 TariffType (Core Structured Tariff)

This is the central new data structure. It replaces text-only tariff communication with a machine-readable format for local cost calculation.

{
  "tariffId": "string",              // REQUIRED. Max 60 chars. Unique identifier.
  "currency": "string",              // REQUIRED. ISO 4217 (e.g. "EUR")
  "validFrom": "date-time",          // Optional. UTC. When absent, immediately active.
  "description": [/* MessageContentType[] */],  // Optional. Human-readable, max 10 items.
  "energy": { /* TariffEnergyType */ },
  "chargingTime": { /* TariffTimeType */ },
  "idleTime": { /* TariffTimeType */ },
  "fixedFee": { /* TariffFixedType */ },
  "reservationTime": { /* TariffTimeType */ },
  "reservationFixed": { /* TariffFixedType */ },
  "minCost": { /* PriceType */ },
  "maxCost": { /* PriceType */ }
}

5.2 TariffConditionsType (New)

Allows conditional pricing based on time-of-day, day-of-week, power levels, energy consumed, etc. All fields are optional; multiple conditions combine with logical AND. Only the first matching price element in a list is used.

5.3 TaxRateType (New)

Supports multi-level stacked taxes (e.g., federal + state).

{ "type": "vat", "tax": 10.0, "stack": 0 }

Tax application order: stack=0 taxes on net price → stack=1 taxes on result → stack=2, etc.

5.4 CostDetailsType (New)

Detailed cost breakdown sent by the CS in TransactionEventRequest. Includes:

5.5 TransactionLimitType (New)

Allows the CSMS to set limits on a transaction via TransactionEventResponse:

{ "maxCost": 50.00, "maxEnergy": 30000, "maxTime": 7200, "maxSoC": 80 }

7.1 MessageContentType

7.2 IdTokenType

7.3 TransactionEventRequest

7.4 TransactionEventResponse

7.5 AuthorizeResponse

7.6 New triggerReason Values for TransactionEventRequest

Mandatory (to comply with 2.1 schema changes)

Required for Local Cost Calculation support

Required for Payment Settlement support

No Changes Required