> ## Documentation Index
> Fetch the complete documentation index at: https://docs.blnkfinance.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Managing Insufficient Funds
> Learn how to handle insufficient funds scenarios in Blnk versions 0.10.8 and older
export const CtaCallout = props => {
const {title, buttonLabel, href, trackingEvent, buttonTarget, rel = "noopener noreferrer", children} = props;
const handleCtaClick = () => {
if (typeof window === "undefined" || !trackingEvent) {
return;
}
try {
window.dispatchEvent(new CustomEvent("blnk:docs-cta", {
detail: {
name: trackingEvent,
href
}
}));
} catch {}
try {
window.posthog?.capture?.(trackingEvent, {
href
});
} catch {}
const gaPayload = {
cta_href: href
};
try {
window.gtag?.("event", trackingEvent, gaPayload);
} catch {}
try {
window.dataLayer = window.dataLayer || [];
window.dataLayer.push({
event: trackingEvent,
...gaPayload
});
} catch {}
};
const isExternal = typeof href === "string" && (/^https?:\/\//i).test(href);
const target = buttonTarget ?? (isExternal ? "_blank" : undefined);
const linkRel = isExternal ? rel : undefined;
return ;
};
This guide is for Blnk versions 0.10.8 and older. For version 0.11.0 and newer, see the [updated documentation](/transactions/introduction#managing-insufficient-funds).
You can manage insufficient funds scenarios in two ways: through automatic rejection handling when transactions are attempted with insufficient balance, and through proactive balance checking before initiating transactions.
### 1. Automatic rejection
When a transaction is posted where the `source` balance has insufficient funds, Bink automatically handles this scenario to maintain ledger integrity. Blnk checks only the balance amount to determine if it is sufficient for the transaction amount being processed.
If funds are insufficient, Blnk:
1. Rejects the transaction.
2. Records this rejection in your ledger using the same state tracking mechanism (i.e. `QUEUED` → `REJECTED`). Learn more about [transaction lifecycle](/transactions/transaction-lifecycle).
3. Sends a webhook notification to inform your system of the state change and new ledger record.
You can also preemptively track the transaction status (via `reference` or `parent_transaction`) to know if the transaction was successful or rejected.
### 2. Proactive balance verification
Instead of waiting for a `transaction.rejected` webhook, you can implement a preemptive available balance check in your workflow. Here's how:
First, query the balance of the sender using:
```bash cURL wrap theme={"system"}
curl -X GET 'http://YOUR_BLNK_INSTANCE_URL/balances/{balance_id}?with_queued=true' \
-H 'X-blnk-key: '
```
```typescript TypeScript wrap theme={"system"}
const response = await blnk.LedgerBalances.get(
'bln_e39a239a-a6ca-4509-b0d9-29dcc5630f8a',
{
with_queued: true,
},
);
```
```json Response {2,8,10} expandable theme={"system"}
{
"balance": 50000,
"version": 0,
"inflight_balance": 0,
"credit_balance": 50000,
"inflight_credit_balance": 0,
"debit_balance": 0,
"inflight_debit_balance": 0,
"queued_credit_balance": 0,
"queued_debit_balance": 15000,
"precision": 100,
"ledger_id": "ldg_073f7ffe-9dfd-42ce-aa50-d1dca1788adc",
"identity_id": "idt_a1b2c3d4-e5f6-7890-abcd-ef1234567890",
"balance_id": "bln_e39a239a-a6ca-4509-b0d9-29dcc5630f8a",
"indicator": "",
"currency": "USD",
"created_at": "2024-07-05T08:13:18.882616461Z",
"meta_data": null
}
```
Next, calculate your available balance:
```
available_balance = balance - inflight_debit_balance - queued_debit_balance
```
* If the available balance is sufficient, proceed with posting your transaction.
* If the available balance is insufficient, you can gracefully handle this scenario in your application by notifying the customer immediately, avoiding the need for webhook handling.
Pending amounts before processing completes.
### 3. Insufficient funds for inflight transactions
Starting from version 0.11.0, Blnk now includes inflight balances in the insufficient funds check. The manual checks described below are only necessary for versions 0.10.8 and older.
When working with inflight transactions, your system must always consider both the actual balance and any pending inflight amounts.
To do this, compute an `available_balance` for your customers indicating the amount available for them to spend on new transactions:
```
available_balance = balance - inflight_debit_balance - queued_debit_balance
```
To check for insufficient funds before initiating an inflight transaction:
1. Query the `source` balance, and compute the `available_balance`:
```
GET /balances/{balance_id}?with_queued=true
```
2. Compare the new transaction amount against `available_balance`:
* **If amount ≤ available\_balance:** Proceed with transaction.
* **If amount > available\_balance:** Handle gracefully in your application by notifying the customer of insufficient funds.
With this approach:
* You ensure that pending inflight transactions will always be committed when they need to.
* Customers are prevented from spending funds that are waiting to be deducted from their balance.
***
## Need help?
We are very happy to help you make the most of Blnk, regardless of whether it is your first time or you are switching from another tool.
To ask questions or discuss issues, please [contact us](mailto:support@blnkfinance.com) or [join our Discord community](https://discord.gg/7WNv94zPpx).
Sign up and manage your ledger with our back-office dashboard. You can invite teammates to collaborate and manage your ledger operations directly from the dashboard.