Fund Wallet

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The Nium Fund Wallet API lets you fund your customer's digital wallet using your iOS, Android, or Windows OS mobile device and your desktop web application.

Funding sources

The supported funding sources or channels for this endpoint include the following:

Funding sourceDescription
PrefundingRequires you to fund the customer wallet before the actual transaction settlement or immediately when a financial institution processes the money. There are no restrictions on the source or destination currency for this funding channel.
Bank transferRequires you to transfer money to a bank account.
CardRequires you to ask Nium to enable this funding channel. Nium restricts this funding source by default.
Direct debitRequires you to ask Nium to allow automatic transactions transferring money from the customer's account to the wallet. Nium restricts this funding source by default.



If the funding channel is a bank transfer or a card, the source and destination currency need to be the same. If the funding channel is a prefund, the source and destination currency can be different.

The following image shows you how to use the fund wallet feature leveraging Fast And Secure Transfers (FAST) and the PayNow service.

Use your own funding

The below image shows how you can set up the payment ID, set up and retrieve a virtual account number (VAN), and get the transaction details.

Your customer initiates the money transfer to fund a multicurrency wallet through their financial institution using their VAN. Then, your financial institution goes through the Inward Credit Confirmation (ICC) to accomplish the transaction. Finally, you post a card wallet funding with an authentication code.

Use third-party funding

The following image shows a sequence diagram of how a third party initiates a money transfer to fund the customer's wallet. The third party's bank account performs the bank transfer with their VAN, to Nium's bank account.

Fund a wallet with a card

  1. A customer successfully onboards Nium using the Electronic Know Your Customer (eKYC) process. The verification method calls Nium's Fund Wallet API with a debit or credit card as a funding channel.
  2. Nium provides a return URL where the customer enters the 3D Secure One Time Password (3DS OTP) verification.
  3. If the 3DS verification fails, the customer restarts the transaction.
  4. If the 3DS verification completes, Nium redirects the customer to a predefined URL that you provide.

The format for the return URL is the following:

  1. Call Nium's [Transactions](ref: transactions) API with the systemReferenceNumber={authCode} query parameter.
  2. If the status is Approved or Declined, you display the status to the customer.
  3. If the status is Pending, you wait to receive the Wallet Funding webhook on success.
  4. You can redirect the customer to any internal page as needed.

Fund a wallet with direct debit

To learn more about how to fund a wallet with direct debit, refer to the Direct Debit user guide.