E-Mobility Transaction Types
This article explains how wholesale, retail, and reimbursement prices are calculated for common charging scenarios in the GreenFlux platform. It also clarifies which market party configures each price, where the resulting costs appear, and when GreenFlux participates in financial settlement.
The scenarios covered are:
- Ad-hoc charging.
- CPO subscriptions.
- Roaming.
- Reimbursement.
For each scenario, we explain:
- The commercial and technical roles involved.
- The applicable cost layers.
- How pricing is configured.
- Where calculated costs are recorded.
- Who is responsible for payment or financial settlement.
Before examining each charging scenario, let us look at the concept of price transparency.
Resource for GreenFlux staff only: As a complement to this article, there is another article, which focus on a deeper technical layer: check.
- Tariff: The overall pricing structure applied to a charging session.
- Tariff code: The identifier used to assign or reference a tariff.
- Billing rule: The conditions and price components used to calculate a cost.
- Wholesale cost: The cost calculated for the CPO or roaming side of a transaction.
- Retail cost: The cost calculated for the driver-facing transaction.
- Reimbursement cost: The amount calculated to compensate a site owner, energy contract holder, fleet driver, or another reimbursement recipient.
- Retail package: The pricing category assigned to a driver or token. The associated retail billing rules contain the actual price logic.
A tariff consists of identifiers, grouping, and one or more billing rules—not only a visible price.
Price transparency across the driver journey
Price transparency is particularly important at two points in the wider EV driver journey:
- Before the session: The driver reviews charger availability and the applicable tariff.
- After the session: The final price is calculated from the communicated tariff and the actual session data.
The journey between these points also includes session authorization, start, monitoring, and stop.
The tariff presented before the session should be consistent with the tariff used for the final calculation. For example, if the only applicable price component is €0.40/kWh and the session delivers 10 kWh, the energy component of the final price should be €4.00. Other configured components, such as a session fee, time fee, parking fee, VAT, discount, grace period, or rounding, may affect the final total.
Concepts and terminology:
- Unit price: A price per unit, such as €0.40/kWh or €0.01/minute.
- Price component: An individual energy, time, parking, or session component.
- Total session price: The final amount charged for the session.
- Cost layer: A wholesale, retail, or reimbursement cost calculated by the platform.
1. Ad-hoc Charging
In an ad-hoc transaction, the EV driver charges without registration or a prior subscription and buys the charging service directly from the CPO. Payment is made at the charging station.
GreenFlux supports several ad-hoc charging channels:
- Charge Assist or a white-label app/web app: The driver starts the session and supplies a payment method through an app or browser.
- CPO-owned app using the Charge Assist API: The CPO controls the customer facing experience and its payment integration.
- Payment terminal integration: The driver pays by card or contactless method through a supported terminal setup.
Note: This process can also be initiated by scanning a QR code displayed on the charger.
A Payment Service Provider (PSP) is normally required to authorize and process the payment.
Ad-hoc: Market roles involved (From the charging service acquisition perspective):
Role | Involvement |
CPO | Sells the charging service directly to the driver |
EV driver | Starts the session and pays without a prior subscription |
eMSP | No roaming eMSP is part of the commercial transaction; a technical eMSP configuration may still exist in the platform |
GreenFlux | May calculate the cost and trigger a PSP request, depending on the implementation |
PSP | Authorizes and processes the card payment |
Ad-hoc: Tariff setup and configurations
The GreenFlux platform does not currently use a dedicated ad-hoc tariff type. Ad-hoc pricing is therefore implemented using:
- A wholesale tariff and wholesale cost calculation.
- A retail package and retail billing rule for the technical ad-hoc setup.
This does not mean that a commercial wholesale relationship exists between the CPO and an eMSP. The wholesale and retail layers are part of the platform’s technical pricing model for the transaction.
For Charge Assist and Charge Assist white-label implementations using the GreenFlux Admin setup, CPOs generally cannot maintain the ad-hoc retail rules independently. Contact your CSM to request or confirm pricing changes for these implementations
Price configuration for Ad-hoc charging:
There are two ways to configure ad-hoc pricing:
- Coupled pricing (WSF > 0): The wholesale cost is used as an input to the retail calculation.
- WSF = 1: Retail cost equals wholesale cost.
- WSF > 1: Retail cost includes a markup over wholesale.
- 0 < WSF < 1: Retail cost is lower than wholesale.
For example, if the wholesale cost is €10 and the WSF is 0.90, the calculated retail cost is €9.
- Independent pricing (WSF = 0): The wholesale cost does not determine the retail cost. The applicable retail billing rule must define an explicit price and scope.
A wholesale price change affects future coupled calculations. It does not automatically rewrite historical CDRs. GreenFlux does not perform currency conversion. When pricing is coupled, the wholesale and retail currency setup must be compatible. Any required conversion must be handled outside GreenFlux.
Check the Retail Billing Engine and Retail tariff configuration page to see in detail how to configure retail packages and retail billing rules.
When in doubt, consult your CSM to ensure the best setup for your case.
Ad-hoc: Data exchange
The relevant wholesale cost is included or communicated through the applicable CDR flow. A GreenFlux-managed eMSP may also have a retail cost calculated by the GreenFlux retail billing engine. An external eMSP normally calculates its retail price outside GreenFlux.
CDRs can be retrieved through the EV Portal or via API integration (Platform API).
See also: Charge Detail Record (CDR) for more details on fields and cost reporting and particularly How do I read costs of a session in a CDR?
Ad-hoc: Financial Clearing
GreenFlux’s role depends on the ad-hoc implementation.
CPO-managed payment flow:
- Example: A CPO-owned app using the Charge Assist API and an independently managed payment provider.
- GreenFlux calculates and records the applicable cost.
- The CPO manages payment authorization, capture, refunds, and settlement with its payment provider.
GreenFlux triggered PSP flow
- Examples may include Charge Assist and supported payment-terminal integrations.
- GreenFlux calculates the final session cost and triggers a request to the configured PSP.
- The PSP processes the payment.
- Funds are settled to the CPO’s PSP account according to the PSP agreement.
The exact authorization, capture, refund, fee, and settlement behavior depends on the selected PSP and integration.
Example
- The driver supplies a payment method and starts the session through Charge Assist.
- The session ends and a successful CDR is created.
- GreenFlux calculates the final session cost and triggers the payment request.
- Stripe processes or captures the payment.
- Funds are settled to the CPO’s Stripe account, subject to the applicable PSP arrangement.
2. CPO Subscription
In a CPO subscription transaction, the driver has a direct commercial relationship with the CPO and charges under a subscription, membership, or preferential pricing arrangement. The CPO operates or manages the charging service. No roaming intermediary is part of the commercial relationship between the driver and CPO.
CPO Subscription: Market roles involved (From the charging service acquisition perspective):
Role | Involvement |
CPO | Provides the charging service and defines the driver offer |
EV driver | Uses the CPO’s subscription or membership |
Roaming eMSP | Not part of the commercial transaction |
GreenFlux | Calculates and records the retail cost |
Payment provider | May be used by the CPO to collect payment |
CPO Subscription: Tariff setup and configurations
CPO-subscription prices are configured through a retail package and its associated retail billing rules.
- The driver or token is assigned to the appropriate retail package.
- The retail package identifies the pricing category.
- The retail billing rules contain the actual pricing logic.
The subscription price can be:
- Coupled to wholesale (WSF > 0)
- Independent of wholesale (WSF = 0)
Wholesale calculation may still exist as part of the platform’s technical model, but only the retail price is relevant to the direct commercial relationship between the CPO and driver.
Check the Retail Billing Engine and Retail tariff configuration page to see in detail how to configure retail packages and retail billing rules.
CPO Subscription: Data Exchange
The relevant wholesale cost is included or communicated through the applicable CDR flow. A GreenFlux-managed eMSP may also have a retail cost calculated by the GreenFlux retail billing engine. An external eMSP normally calculates its retail price outside GreenFlux.
CDRs can be retrieved through the EV Portal or via API integration (Platform API).
See also: Charge Detail Record (CDR) for more details on fields and cost reporting and particularly How do I read costs of a session in a CDR?
CPO Subscription: Financial Clearing
GreenFlux does not handle financial clearing for CPO subscriptions. Its role is limited to cost calculation and recording in the CDRs. Actual payments flow needs to be handled by the CPO.
3. Roaming
In a Roaming transaction, the CPO provides charging services to an eMSP, which then resells them to the EV driver. This introduces two sub-transactions:
- Wholesale transaction: CPO → eMSP. In GreenFlux managed roaming, this is actually split in 2 transactions, as depicted in picture above. (GreenFlux staff only: More details at link)
- Retail transaction: eMSP → Driver
Roaming: Market roles involved (From the charging service acquisition perspective):
Role | Responsibility |
CPO | Provides the charging infrastructure and sets or agrees the applicable wholesale price |
eMSP | Buys the charging service and determines the driver-facing retail price |
EV driver | Authorizes through the eMSP and pays the eMSP |
GreenFlux | Facilitates data exchange and, for managed roaming, participates in wholesale settlement |
Roaming: Tariff setup and configurations
Because roaming involves both wholesale and retail layers, tariffs must be defined separately for CPOs and eMSPs.
1. CPO → eMSP (Wholesale)
- Tariffs are configured in the wholesale billing engine.
- The applicable wholesale tariff may include energy, time, parking, and session price components. The resulting wholesale cost is calculated for the completed charging session.
- Output: The calculated wholesale cost used in the applicable invoicing or settlement process.
2. eMSP → Driver (Retail)
The eMSP determines the driver-facing price using the retail billing engine for drivers or tokens managed in the GreenFlux platform.
The retail price may be:
- Coupled to the wholesale cost (WSF > 0)
- Independent of the wholesale cost (WSF = 0)
For externally managed eMSP tokens, GreenFlux may only provide the wholesale CDR information; the external eMSP calculates the driver price in its own system.
GreenFlux does not perform currency conversion. If the eMSP needs to invoice the driver in a different currency, the conversion must be managed by the eMSP outside GreenFlux.
Further details check:
Roaming: Data Exchange
The relevant wholesale cost is included or communicated through the applicable CDR flow. A GreenFlux-managed eMSP may also have a retail cost calculated by the GreenFlux retail billing engine. An external eMSP normally calculates its retail price outside GreenFlux.
CDRs can be retrieved through the EV Portal or via API integration (Platform API).
See also: Charge Detail Record (CDR) for more details on fields and cost reporting and particularly How do I read costs of a session in a CDR?
Roaming: Financial Clearing
Financial clearing in roaming must be understood across the two sub-transactions. It must be considered separately for the retail and wholesale relationships.
1. Retail settlement
Driver and eMSP: The driver pays or is invoiced by the eMSP. GreenFlux may calculate a retail cost for internally managed drivers, but it does not settle the payment between the driver and eMSP.
2. Self-managed wholesale settlement
Self-managed roaming: The CPO and eMSP manage their commercial agreement, invoicing, and settlement directly. GreenFlux facilitates CDR and cost-data exchange but does not act as the wholesale financial counterparty.
3. GreenFlux-managed wholesale settlement
GreenFlux-managed roaming: GreenFlux participates in the wholesale commercial chain:
- GreenFlux purchases the charging service from the CPO.
- GreenFlux sells the charging service to the eMSP.
- Settlement documents are issued according to the applicable managed-roaming agreement.
Under GreenFlux-managed roaming, GreenFlux is the CPO’s wholesale counterparty for transactions covered by the applicable managed-roaming agreement.
Layer | Responsible party | Result | Settlement |
Wholesale | CPO/applicable roaming setup | Wholesale cost | Direct CPO–eMSP or GreenFlux-managed |
Retail | eMSP | Driver-facing retail cost | Driver–eMSP |
Reimbursement | CPO/operator | Reimbursement cost | Normally outside GreenFlux |
4. Reimbursement
In a reimbursement transaction, the platform calculates an amount used to compensate an energy contract holder or another reimbursement recipient for charging-related electricity costs.
Common examples include:
- A CPO reimbursing a site owner or landlord.
- A company reimbursing a fleet driver for business charging at home.
- An operator reimbursing another party that pays the electricity bill.
Role | Involvement |
CPO/operator | Configures or uses the reimbursement calculation |
Reimbursement recipient | Receives the reimbursement amount |
Driver/eMSP | May be part of the underlying charging transaction but is not necessarily the reimbursement recipient |
GreenFlux | Calculates and records the reimbursement cost |
Reimbursement: Tariff setup
Reimbursement prices are configured through reimbursement tariffs and reimbursement billing rules.
Two pricing models are possible:
- Wholesale-linked reimbursement: The wholesale cost is used as an input to the reimbursement calculation.
- Independent reimbursement: The reimbursement billing rule contains an explicit price that does not depend on wholesale cost.
When reimbursement is linked to wholesale pricing, future calculations use the applicable wholesale cost. Historical CDRs are not automatically rewritten.
Check the Reimbursement Billing Engine and reimbursement tariff configuration page to see in detail how to configure reimbursement tariffs and reimbursement billing rules.
Reimbursement: Data exchange
The relevant wholesale cost is included or communicated through the applicable CDR flow. A GreenFlux-managed eMSP may also have a retail cost calculated by the GreenFlux retail billing engine. An external eMSP normally calculates its retail price outside GreenFlux.
CDRs can be retrieved through the EV Portal or via API integration (Platform API).
See also: Charge Detail Record (CDR) for more details on fields and cost reporting and particularly How do I read costs of a session in a CDR?
Reimbursement: Financial clearing
For reimbursement transactions, GreenFlux does not participate in financial clearing.
- The platform’s role is limited to calculating reimbursement costs and recording them in the CDRs.
- The actual reimbursement payments are handled outside GreenFlux, between the CPO and the site owner (energy contract holder).
Where calculated costs appear
Applicable costs are recorded in a Charge Detail Record after a successful charging session.
CDRs can be:
- Viewed in EV Portal.
- Exported from EV Portal.
- Retrieved using the Platform API.
- Exchanged with roaming partners through the applicable technical connection.
The available cost fields and terminology depend on:
- The interface.
- The transaction type.
- Whether the CPO, eMSP, or token is managed in GreenFlux.
- The permissions and role of the party viewing the CDR.
A CDR does not necessarily contain every cost layer. For example, GreenFlux normally does not calculate retail costs for a driver belonging to an external eMSP.
Currency considerations
Each calculated cost has an applicable currency. GreenFlux does not perform currency conversion.
When a retail or reimbursement cost is coupled to wholesale pricing, the relevant currency configuration must be compatible with the wholesale cost.
If an eMSP wants to invoice drivers in another currency, the eMSP must perform the conversion outside GreenFlux.
Changing an existing billing rule
Avoid editing the meaning of an active pricing rule without considering its validity period.
A common process is:
- Copy the existing rule.
- Update the price, scope, or validity dates in the copied rule.
- Save the new rule.
- Expire the previous rule so the validity periods do not overlap unintentionally.
Wholesale pricing changes may be subject to an activation or publication lead time of approximately five weeks. Retail rules do not use the same wholesale lead-time requirement.
Current operational guidance distinguishes copying and expiring rules and confirms that the wholesale lead time still applies