> ## Documentation Index
> Fetch the complete documentation index at: https://docs.fluz.app/llms.txt
> Use this file to discover all available pages before exploring further.
# Open Loop Card Funding Sources
> Set which spend account pays for each hosted open-loop card you generate.
Open-loop cards are funded from **your** account, not the recipient's. When someone claims a hosted card link and spends it, the money comes out of a spend account you nominate at the moment you generate the link.
**The funding options here are narrower than on `createVirtualCard`.**
The open-loop path exposes exactly one funding control: `userCashBalanceId`. There is no `primaryFundingSource`, no `bankAccountId`, no `usePrepaymentBalance`, and no `useRewardsBalance`. External bank accounts cannot fund an open-loop card — the spend account must be funded first.
If you are porting an integration from `createVirtualCard`, do not assume the same fields carry over. See [Differences from standard cards](#differences-from-standard-cards).
***
## Setting the funding source
Pass `userCashBalanceId` on [`generateVCShareLinks`](/features/open-loop-cards/send-open-loop-cards). It applies to every card generated in that request.
```graphql theme={null}
mutation GenerateVCShareLinks($input: GenerateVCShareLinksInput!) {
generateVCShareLinks(input: $input) {
shareRequestId
generatedShareLinks {
linkUrl
status
}
}
}
```
```json theme={null}
{
"input": {
"offerId": "ed669305-5e43-40a0-9a25-7a15ed174628",
"userCashBalanceId": "b1155504-ad30-4b2f-873d-b8795277b128",
"shareMethod": "GENERATE_URL",
"spendLimit": 50.00,
"daysUntilExpiration": 30
}
}
```
**`userCashBalanceId` is marked optional in the schema, but treat it as required.**
Omit it and the cards fall back to a default balance on your account. For a payout or rewards program that is almost never what you want — it makes spend unattributable and puts campaign disbursements against general account funds. Always set it explicitly, on every request.
This mutation requires a Bearer token with the `CREATE_SHARE_LINK` scope. Basic auth is rejected.
***
## Per-card funding across a batch
`userCashBalanceId` is set per **request**, not per link. Every card in one `generateVCShareLinks` call draws from the same spend account.
To fund different cards from different accounts, issue one request per funding source:
```typescript theme={null}
// One request per campaign, each pointed at its own spend account.
const campaigns = [
{ name: 'Q3 referral', cashBalanceId: 'b1155504-...', limit: 25, count: 200 },
{ name: 'Q3 win-back', cashBalanceId: 'c2266615-...', limit: 50, count: 50 },
];
for (const campaign of campaigns) {
await graphql(
`mutation GenerateVCShareLinks($input: GenerateVCShareLinksInput!) {
generateVCShareLinks(input: $input) {
shareRequestId
generatedShareLinks { linkUrl status }
}
}`,
{
input: {
offerId,
userCashBalanceId: campaign.cashBalanceId,
shareMethod: 'GENERATE_URL',
spendLimit: campaign.limit,
daysUntilExpiration: 30,
},
},
);
}
```
**Use one spend account per program, not one shared pot.** A dedicated spend account per campaign gives you a clean balance to reconcile against, an obvious place to see remaining exposure, and a natural stopping point if something goes wrong — draining one account cannot touch another. It also means [`getSpendAccountVirtualAccountNumbers`](/features/virtual-account-numbers) gives that campaign its own routing and account number for direct funding.
***
## Funding the spend account
Because open-loop cards cannot pull from an external bank at spend time, the spend account has to hold funds before recipients start claiming. Three ways to get money in:
| Method | Use when |
| :--------------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------------------------ |
| [Deposit from an external account](/features/deposit-from-external-accounts) | Standard top-up from a linked bank account or card. |
| [Virtual account numbers](/features/virtual-account-numbers) | You want to push funds in by ACH, wire, RTP, or FedNow. Each spend account gets its own routing and account number. |
| [Transfer between spend accounts](/features/transfer-between-spend-accounts) | Moving budget from one program to another. |
Check the balance before a large batch with [`getUserCashBalances`](/features/get-spend-accounts), reading `availableCashBalance` rather than `totalCashBalance`.
***
## Differences from standard cards
| Control | `createVirtualCard` | `generateVCShareLinks` |
| :---------------------------- | :----------------------------------------------------- | :--------------------- |
| Specific spend account | `userCashBalanceId` | `userCashBalanceId` |
| External bank account | `primaryFundingSource: BANK_ACCOUNT` + `bankAccountId` | Not available |
| Prepayment balance | `usePrepaymentBalance` | Not exposed |
| Rewards balance | `useRewardsBalance` | Not exposed |
| Change funding after issuance | `editVirtualCard` | Not available |
The practical consequence: open-loop programs are **prefunded**. You cannot run them off an external bank account the way you can run a standard corporate card, so treat spend account balance as an operational requirement and monitor it.
For the full picture on standard cards, see [Manage Virtual Card Funding Sources](/features/virtual-card-funding-sources).
***
## Common mistakes
Neither field exists on `GenerateVCShareLinksInput`. Open-loop cards are funded from a spend account only. Fund the spend account first, then generate links against it.
It is optional in the type definition but effectively required in practice. Without it your cards draw from a default balance, and campaign spend becomes impossible to attribute or cap.
There is no edit path for an issued share link's funding. If you nominated the wrong spend account, deactivate the links with `deactivateVCShareLinks` and generate a new batch.
Confirm `availableCashBalance` covers the batch — `spendLimit` multiplied by the number of links — before generating. A batch that outruns its funding fails at the recipient, not at your API call, which means your support team hears about it before you do.
***
Generating, listing, and deactivating hosted card links.
The four ways to get a card link to a recipient.
Give each program's spend account its own routing and account number.
The fuller set of funding controls on standard cards.