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10 Workflows

The workflow provides a detailed view of how the payments BB will interact with other building blocks to support common use cases.

10.2 G2P Bulk Payment Workflow

10.2.1 Bulk Disbursement for Unconditional Cash Transfer Prerequisites

Before bulk payments are made the following are prerequisites:
Funding requirements
  • The funding requirements must operate within the budget/ceiling.
  • The number of funding accounts and the life cycle processes will vary depending on the payment infrastructure scenarios.
Bulk payments file
  • For the salary payments use case, this would be generated by the payroll system.
  • For the unconditional social cash transfer use case, this would be generated by a process that would be triggered as per a pre agreed frequency and the information about the payments to be made would be extracted from the registry (database containing the information about beneficiaries for a particular government social cash transfer programme). The process generating this payments file is outside the payments building block. Description

There are three options for the disbursement,
  • Manual process for Govt/Dept to send the retail payment details for each FSP (ie either by email or other means). This would be the case where there is a lack of interoperability among FSPs.
  • Upload the batch disbursement file in the payment web portal for each FSP to retrieve in the case of a centralised Account Lookup Directory Service.
  • Automate the disbursement process through the decentralised Account Lookup Directory Service and the payment gateway.
Option 1: Retail Payment Information is Sent Securely to Each Payment Service Provider for Disbursement
Payments building block diagrams.drawio -
Option 2: Retail payments are accessed via a payment web portal by the Payment Service Provider the advice/electronic fund transfer request, or paper-based check is issued from the Financial Management Information System to the TSA-holding Bank. Based on this advice, the Bank disburses funds from the Trusted Single Account (TSA) into the digital payments system of the FSP which transfers the corresponding funds to the recipient’s account. For the retail payment scrolls, where each agency is responsible for running the payment system - payroll, social welfare payments, etc - the payment details are not stored in those systems. Instead, the beneficiary’s payment token is retrieved from the Centralised Account Lookup Directory Service and kept in the government payment portal.. The payment lists are only shared with the program account holder institution/FSP, PSP, via the government payment portal. The FSP/PSP can log in on the government web portal to access the directory for payments that the FSP needs to effect for each G2P Program.
Payments building block diagrams.drawio -
Option 3: Similar to option 2 but the disbursement process to the beneficiary is routed automatically through the payment gateway using the payment token retrieved from the decentralised account lookup directory service.
Payments building block diagrams.drawio -
Bulk payments require the functionality of a Payments Gateway and the functionality therein. It also assumes a separate mechanism by which the recipient account address is determined. In the figure below the “account lookup directory service” functionality maps the concept of identity to the payment alias and from there to the FSP (financial service provider) routing address. (i.e. wallet address or account address) Interaction with Other Building Blocks
This workflow requires interaction with the registries building Blocks
At a high level, the payment components used for bulk payments are shown in the figure below.
Payments building block diagrams.drawio -
Figure: Key digital requirements of Bulk Payments expressed as a high level block diagram. Dotted line for required components.
Payments building block diagrams.drawio - Sequence Diagram
The sequence diagram shows the flow of data between building blocks for bulk payments workflow.
  • The Beneficiary system (registry BB) transmits the compiled list with boundary conditions for payment timings for each G2P programme (i.e. staggered, each week, standing, etc.).
  • Bulk payment services validate data structures and content in compiled lists.
  • Bulk payment service uses the Account Lookup (Directory) Service (ALS), a type of Discovery Service that is more protective of account information and privacy. The ALS is used to establish the destination FSP, and the payment alias is then provided by the destination FSP. These functions are used when the account address is not specified in advance. The discovery service can also be used to verify whether the account address information provided by the beneficiary system is valid (this would be in the event the payment information is provided by the beneficiary system to the payments BB directly).
  • FSP validates account exists and provides status of account.
  • Bulk payment service prepares the batch breakdown on the basis of rulesets governing which FSPs shall receive which payments, combinating payments with other payments to the same beneficiary, etc.
  • In the case of salary payments, there is a single entry in the payment instruction file sent to the bulk payments service.
  • FSP returns a quote on the fees to be charged.
  • Bulk payment service sends the batch to each FSP with payment instructions.
  • FSP notifies the end beneficiary who then requests the payment via a channel (Merchant POS, Agent, mobile banking, wallet account feature, bank transfer, voucher).
  • Beneficiary is paid and the success is communicated back to the Beneficiary system (as well as error codes).
Bulk payment service system does reconciliation on accounts paid/not paid and communicates that back to the beneficiary system as well.

10.2.2 Disbursement to Beneficiary Using Mobile Money

In order to facilitate the transfer of funds from the disbursement organisation (the payer) to the mobile money provider, the mobile money provider would need to be connected to the payment gateway / switch. Should this connection not be in place, the disbursement could be facilitated by a third-party aggregator or there would need to be a bilateral connection between the payer’s FSP and the Mobile Money Provider. Interaction with Other Building Blocks

This workflow requires interaction with the registry Building Blocks
The disbursement organisation (payer) gives instruction to its FSP to process a bulk disbursement to a number of mobile money recipients (Healthcare workers).
The payer’s FSP forwards the bulk payment instructions to the Bulk payment service which validates the list and queries the ID directory service to determine the recipients mobile money providers. The ID directory returns the list of the recipients providers to the BB which would then create separate batches for each mobile money provider.
The bulk payments service sends the batch and payment instructions to the payer’s FSP which processes the transfer through the gateway which forwards the payment to the correct Mobile Money Provider.
The Mobile Money provider would then credit the beneficiaries accounts who would receive a notification, confirming the amount has been credited to their accounts. Upon payment success, the Mobile Money provider would notify the payer’s FSP of the payment completion

10.3 G2P Beneficiary Payments Using Vouchers

10.3.1 Description

The Voucher Management System supports at least three workflows for:
  1. 1.
    administration (voucher provisioning and merchant registration),
  2. 2.
    voucher issuing (pre-activation and activation) and
  3. 3.
    redemption use cases as shown in the diagram below. These use cases and the relationship between each one of them is shown and further described below.below.
The use cases are described in the section below:
Payments building block diagrams.drawio - Admin Process

These processes are usually done prior to the issuance of the voucher to ensure a smooth flow at the point of issuance.
The Admin processes for the Voucher Management Server cover the lifecycle of the vouchers and are typically performed by a privileged user (this may be done through User Interface or an API). These processes include but are not limited to creating voucher groups, provisioning vouchers, suspending vouchers, unsuspending vouchers, validating vouchers, key management and purging of used vouchers.
  • Voucher Provisioning This function will be done by an administrator (privileged user). It will typically be triggered by the deposit of funds in a funding account, thus the source account. Voucher provisioning creates a conditional right to funds, and an inventory of issued-vouchers. Other processes related to this are voucher inventory management, voucher suspension and voucher purging.
  • Merchant Registration In order for efficient redemption of vouchers merchants MUST be registered in advance to create a network of trusted providers. This registration is assumed to be managed by the Registration BB, The account verification of the merchant can be done at registration or during redemption subject to a configuration During the registration process, merchants MAY also be assigned to different voucher groups depending on the required function that has been implemented. For example, there may be a voucher group for schools. This implies that vouchers of this type can only be redeemed at schools. This also requires that the use flow system at which the voucher is issued is aware of these voucher groups and is able to send the appropriate request to the Voucher Management System..
  • Agent Registration In markets where cash outs are being used, it is expected that the Registration BB will register agents in a similar way.
  • Voucher Groups Depending on the requirement it should also be possible to set up multiple voucher groups. Vouchers in the same voucher group will have similar characteristics and are labeled with a specific voucher group name. During voucher provisioning, a voucher can be created and attached to a single voucher group.. When a voucher is requested (using the pre-activation API) it is expected that the voucher group will be one of the parameters set.
  • Voucher Issuing Voucher issuing is triggered by the registrations building block which will determine whether the conditions of issuance have been met. The calling block will determine the denomination and voucher group of the voucher to be issued. The voucher number and the voucher serial number that is issued can be presented to the beneficiary in multiple ways including but not restricted to encoding in the form of QR codes, bar code, printed voucher or even SMS. This is outside the scope of the Payment BB. It is expected that Building Blocks through which the voucher is redeemed will also be able to decode the voucher Interaction with Other Building Blocks

This workflow requires interaction with the Registration and Merchant registry Blocks Sequence Diagram

The sequence diagram shows the flow of data between building blocks for this workflow
Voucher Activation
The voucher activation flow is shown in the diagram below.
Link to edit:
Flow Description:
  • An external Building Block may invoke the Payment BB API gateway to pre-activate API on the Voucher Management Server with the amount of the voucher, the voucher currency and the voucher group. The calling block may optionally send a comment. The comment will be stored by the voucher server. The voucher group will indicate that it is looking for a voucher from a specific voucher group. This API call will be made through the payment orchestrator.
  • The voucher group is typically used for the conditional social transfer (e.g. for school fee payment). If any voucher can be used for any purpose, then all vouchers should be created with a generic voucher group (e.g. “GENERAL-PURPOSE”).
  • The API returns to get a voucher number, the voucher serial number and its expiry date. At this point the voucher will be flagged Pre-Activated.
  • The calling Building Block may render the voucher as a QR code, as a barcode or even an SMS text. It is recommended that the voucher should include supplementary data of the recipient. It is also recommended that this data should also be printed in human readable form so that the recipient can verify the data on the voucher. This data can also be verified at the point of redemption.
  • Once the calling API successfully prints / issues the QR code, the voucher can then be activated using the activation API. It is assumed that there will not be a substantial delay between pre-activation and activation to necessitate the need for multiple expiry periods.
Alternative: the voucher could be activated immediately on being requested. This could be controlled at the Payment Orchestrator..
  • Preconditions
    • The calling registration block will determine that all the necessary preconditions are met.
    • The most critical precondition is the prefunding which will be done manually at voucher provisioning stage. (Other options that could be prefunding triggered by activation or at redemption which are not considered because they are considerably more complex and create additional failure points in the activation of the vouchers.)
  • Assumptions / Queries
    • It is assumed that only one currency will be used.
    • A zero-trust architecture.
    • The transaction is not reversible.
  • Post-Condition The calling BB may invoke another payment BB API e.g. initiating an incentive payment for the agent.
Voucher Redemption
The voucher redemption is shown in the diagram below.
Link to edit:
Flow Description:
  • At redemption the beneficiary shows the voucher to the merchant or agent.
  • The merchant / agent will scan and interpret the medium in which the voucher is presented (this could be a QR code or a barcode or an SMS or even a printed number).
  • Voucher redemption Validation: The details presented MAY allow the merchant / agent to authenticate/validate the owner of the voucher.
  • The agent will then initiate the redemption process which will call the Payment BB API Management Gateway.
  • The API Management Gateway will validate the voucher and initiate the payment through the payment gateway.
  • If specific voucher groups have been set up, voucher usage may be restricted to specific merchants. An override parameter should also be provided that will allow a Voucher of any voucher group to be redeemed at any merchant.
  • Once the payment to the merchant / agent is successful the Payment gateway will inform the API Management Gateway.
  • The API Management Gateway will then instruct the VMS API to flag the voucher as consumed.
  • Payments could be made through a switch in which case there would be no need for prefunding accounts in each financial institution.
  • The merchant must have been registered possibly by the Registration BB with their preferred payment method.
  • The merchant must have a mechanism (e.g. a mobile APP, USSD app or SMS option) to verify the beneficiary prior to redemption.
  • The app for reading the QR code and redemption are not part of the scope of the Payment BB.
  • The entire voucher amount is consumed. Partial redemption will not be allowed.
  • The amount that is paid to the merchant or agent is debited from a prefunded account.
Sample Redemption
Source: Kenya Government and WFP Disburse Relief Cash to Drought Stricken Families accessed 05-Sep-21
In the case of a physical voucher the voucher number or the secret number is hidden behind some material that must be scratched away to see the number. The voucher number is also commonly known as the PIN.
Voucher Cancellation
The voucher cancellation flow is shown in the diagram below.
Flow Description:
  • The calling Building Block will request the API Management Gateway to cancel a Voucher.
  • The API Management Gateway will invoke the VMS API to cancel the Voucher.
  • The VMS API interface will check if the Voucher is valid and then cancel the Voucher.
  • The VMS API interface will confirm that the Voucher has been canceled.
  • If the Voucher does not exist, the VMS API will respond that the Voucher does not exist.
  • If the Voucher is already consumed, the VMS API will respond that the Voucher is already consumed.
  • If the Voucher is already canceled the VMS API will respond that the Voucher is already canceled.
  • If the Voucher is suspended the VMS API will respond that the Voucher is suspended.
Voucher Technical Requirements
Type (Must/Should/May)
Voucher Provisioning
High volume generation of vouchers
Voucher numbers must be unique and not predictable
Logs must not capture voucher numbers
Voucher Storage (will this be in a separate BB)
Secure storage
High Availability
API invoked to get voucher number and serial number
API to redeem voucher
API to invoke payment gateway
  • All calls from external parties (e.g. Registration BB) to the voucher management system will be initiated through the API management gateway.
  • The payment orchestration module may direct transitions between the various functions.
  • The discovery service could be called by other building blocks to determine where bank accounts / wallets sit.
  • The only function that speaks to the DFS is the payment gateway. Any function that needs to speak to the DFS goes through the Payment gateway.
  • The Payment gateway may need to speak to a Number Portability provider.
  • Audit trails (transaction logs) capture each event as it happens and are to be used for queries, analysis and reconciliation.
  • Event logs will capture specific events that happen at each node.

10.4 P2G Payments

A P2G payment is a payment made by a person to the government or a government agency in exchange for a service provided.

10.4.1 Description

The following P2G payments using mobile applications are considered.
  • Government initiated - request to pay
  • Mobile payments
    • With QR codes
    • with reference ID (payment transaction ID)
  • Banking channels
    • with reference ID

10.4.2 Interaction with Other Building Blocks

This workflow requires interaction with the messaging BB an the registration building block

10.4.3 Sequence Diagram - P2G Payment

General Notes:
  • It is assumed that all APIs used are real (sync or async).
Link to Edit Diagram
Flow Description:
  • Upon registration for a government service, the registration building block sends transaction details to the payment building block which creates and returns a unique payment reference for the payer of the service.
  • The registration building block sends the unique reference number to the payer.
  • After entering their account the payer would invoke a bill payment to a selected service (in this case paying for the registration service). The payer would need to enter the payment reference which would prompt the retrieval of the payment details from the registration building block in real time. If the payment details are correct, the payer is prompted to enter his / her mobile money pin to authorize the payment.
  • Upon authorisation, the payer’s account is debited and the government’s connected account is credited in real time. The FSP, in this case the mobile money provider would then notify the success status to the payment building block.
  • For this type of payment, as the payment reference is needed to validate the payment, this can be done by any mobile money account holder.
The above model requires that the payer must provide two pieces of information through their USSD, STK or mobile app:
  • A merchant ID. Typically the government would be given a special merchant ID. The payer should be able to select which government service he/she would be paying through the mobile money interface.
  • A reference ID: this is unique and time bound for each transaction.
  • As the bill payment is invoked by inputting the reference number which prompts the retrieval of the payments details in real time from the registration building block, a failed transaction could be triggered by a session time-out or a wrong PIN. In both cases the payer would have to re-initiate the transaction.
  • In the P2G payment in the flow above, the government holds an account with the FSP which would collect the payments on the government behalf and transfer it to the single treasury account on a defined timeline (i.e. daily) in an aggregated way. For reconciliation purposes, the registration BB would need to notify the government of a successful / unsuccessful payment.

10.4.4 Sequence Diagram - P2G FSP Payment by USSD Prompt

Flow Description:
  • Upon registration for a government service, the registration building sends transaction details to the payment building block which sends a payment request to the payer through his / hers mobile money provider (USSD prompt).
  • The payer will see a request coming for the specific service requested with payment details, prompting him / her to authorize the payment by entering the pin code.
  • Upon authorisation, the payer’s account is debited and the government’s connected account is credited in real time.
  • The FSP, in this case the mobile money provider would then notify the success status to the payment building block.
  • This payment differs from the previous P2G mobile money payment as the payment is not initiated by the payer by invoking a bill payment but is initiated by a merchant (in this case the government agency providing the service. Therefore the payer is requested to pay for the service immediately.
  • There can be no error in the above as both the merchant number and the payment reference are pushed to the phone.
  • The only risk here is a timeout on the USSD or the user keying in the wrong PIN which may require the transaction to be reinitiated.

10.4.5 Sequence Diagram - P2G Payment with QR Code

  • There is small room for error in reading a QR code (unless the payer scans the wrong code).
  • All mobile operator and banking apps need to be able to read the reference in the same way for this to work meaning that a standardised / interoperable QR code needs to be in place at a country level. While this is in place in some Asian countries (i.e. Indonesia, Sri Lanka) where there is a widespread adoption of QR codes, In Africa the uptake of QR codes is significantly lower and standardisation is typically not in place at a country level. QR Code Payment Flow Use Case Example
  1. 1.
    During registration, the registration BB will generate transaction details including amount to be paid by the payer and transaction ID and send to the payments building block.
  2. 2.
    The payments building block will use the transaction details to initiate a request to pay to the FSP.
  3. 3.
    The QR payment widget displayed to the payer will have the following different attributes
    1. 1.
    2. 2.
    3. 3.
    4. 4.
  4. 4.
    The payer scans the QR code to approve/reject the payment.
  5. 5.
    The FSP sends a notification of the status of the transaction to the payments BB and the payer.
  6. 6.
    Transaction status sent to the registration building block on completion of payments.
  7. 7.
    The messaging building block sends a transaction confirmation message to the payer.
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