Internal Accounts

Internal accounts are Lightspark managed accounts that hold funds within the Grid platform. They allow you to receive deposits and send payments to external bank accounts or other payment destinations. They are useful for holding funds on behalf or the platform or customers which will be used for instant, 24/7 quotes and transfers out of the system. Internal accounts are created for both:

Platform-level accounts: Hold pooled funds for your platform operations (rewards distribution, reconciliation, etc.)
Customer accounts: Hold individual customer funds for their transactions

Internal accounts are automatically created when you onboard a customer, based on your platform’s currency configuration. Platform-level internal accounts are created when you configure your platform with supported currencies.

How internal accounts work

Internal accounts act as an intermediary holding account in the payment flow:

Deposit funds: You or your customers deposit money into internal accounts using bank transfers (ACH, wire, PIX, etc.) or crypto transfers
Hold balance: Funds are held securely in the internal account until needed
Send payments: You initiate transfers from internal accounts to external destinations

Each internal account:

Is denominated in a single currency (USD, EUR, etc.)
Has a unique balance that you can query at any time
Includes unique payment instructions for depositing funds
Supports multiple funding methods depending on the currency

Retrieving internal accounts

List customer internal accounts

To retrieve all internal accounts for a specific customer, use the customer ID to filter the results:

Request internal accounts for a customer

curl -X GET 'https://api.lightspark.com/grid/2025-10-13/customers/internal-accounts?customerId=Customer:019542f5-b3e7-1d02-0000-000000000001' \
  -u "$GRID_CLIENT_ID:$GRID_CLIENT_SECRET"

Response

{
  "data": [
    {
      "id": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965",
      "customerId": "Customer:019542f5-b3e7-1d02-0000-000000000001",
      "type": "INTERNAL_FIAT",
      "status": "ACTIVE",
      "balance": {
        "amount": 50000,
        "currency": {
          "code": "USD",
          "name": "United States Dollar",
          "symbol": "$",
          "decimals": 2
        }
      },
      "totalBalance": {
        "amount": 50000,
        "currency": {
          "code": "USD",
          "name": "United States Dollar",
          "symbol": "$",
          "decimals": 2
        }
      },
      "fundingPaymentInstructions": [
        {
          "instructionsNotes": "Include the reference code in your ACH transfer memo",
          "accountOrWalletInfo": {
            "reference": "FUND-ABC123",
            "accountType": "USD_ACCOUNT",
            "accountNumber": "9876543210",
            "routingNumber": "021000021",
            "accountHolderName": "Lightspark Payments FBO John Doe",
            "bankName": "JP Morgan Chase"
          }
        },
        {
          "accountOrWalletInfo": {
            "accountType": "SOLANA_WALLET",
            "assetType": "USDC",
            "address": "4Nd1m6Qkq7RfKuE5vQ9qP9Tn6H94Ueqb4xXHzsAbd8Wg"
          }
        }
      ],
      "createdAt": "2025-10-03T12:00:00Z",
      "updatedAt": "2025-10-03T14:30:00Z"
    }
  ],
  "hasMore": false,
  "totalCount": 1
}

Filter by currency

You can filter internal accounts by currency to find accounts for specific denominations:

curl -X GET 'https://api.lightspark.com/grid/2025-10-13/customers/internal-accounts?customerId=Customer:019542f5-b3e7-1d02-0000-000000000001&currency=USD' \
  -u "$GRID_CLIENT_ID:$GRID_CLIENT_SECRET"

List platform internal accounts

To retrieve platform-level internal accounts (not tied to individual customers), use the platform internal accounts endpoint:

curl -X GET 'https://api.lightspark.com/grid/2025-10-13/platform/internal-accounts' \
  -u "$GRID_CLIENT_ID:$GRID_CLIENT_SECRET"

Platform internal accounts are useful for managing pooled funds, distributing rewards, or handling platform-level operations.

Understanding funding payment instructions

Each internal account includes fundingPaymentInstructions that tell your customers how to deposit funds. The structure varies by payment rail and currency:

US ACH or wire transfers

For USD accounts, instructions include routing and account numbers:

{
  "instructionsNotes": "Include the reference code in your ACH transfer memo",
  "accountOrWalletInfo": {
    "accountType": "USD_ACCOUNT",
    "reference": "FUND-ABC123",
    "accountNumber": "9876543210",
    "routingNumber": "021000021",
    "accountHolderName": "Lightspark Payments FBO John Doe",
    "bankName": "JP Morgan Chase"
  }
}

Each internal account has unique banking details in the accountOrWalletInfo field, which ensures deposits are automatically credited to the correct account.

SEPA EUR transfers

For EUR accounts, instructions use SEPA IBAN numbers:

{
  "instructionsNotes": "Include reference in SEPA transfer description",
  "accountOrWalletInfo": {
    "accountType": "EUR_ACCOUNT",
    "reference": "FUND-EUR789",
    "iban": "DE89370400440532013000",
    "swiftCode": "DEUTDEFF",
    "accountHolderName": "Lightspark Payments FBO Maria Garcia",
    "bankName": "Banco de México"
  }
}

Spark Stablecoin Funding

For stablecoin accounts, using a Spark wallet as the funding source:

{
  "invoice": "lnbc15u1p3xnhl2pp5jptserfk3zk4qy42tlucycrfwxhydvlemu9pqr93tuzlv9cc7g3sdqsvfhkcap3xyhx7un8cqzpgxqzjcsp5f8c52y2stc300gl6s4xswtjpc37hrnnr3c9wvtgjfuvqmpm35evq9qyyssqy4lgd8tj637qcjp05rdpxxykjenthxftej7a2zzmwrmrl70fyj9hvj0rewhzj7jfyuwkwcg9g2jpwtk3wkjtwnkdks84hsnu8xps5vsq4gj5hs",
  "instructionsNotes": "Use the invoice when making Spark payment",
  "accountOrWalletInfo": {
    "accountType": "SPARK_WALLET",
    "assetType": "USDB",
    "address": "spark1pgssyuuuhnrrdjswal5c3s3rafw9w3y5dd4cjy3duxlf7hjzkp0rqx6dj6mrhu"
  }
}

Solana Stablecoin Funding

For Solana wallet accounts, using a Solana wallet as the funding source:

{
  "accountOrWalletInfo": {
    "accountType": "SOLANA_WALLET",
    "assetType": "USDC",
    "address": "4Nd1m6Qkq7RfKuE5vQ9qP9Tn6H94Ueqb4xXHzsAbd8Wg"
  }
}

Tron Stablecoin Funding

For Tron wallet accounts, using a Tron wallet as the funding source:

{
  "accountOrWalletInfo": {
    "accountType": "TRON_WALLET",
    "assetType": "USDT",
    "address": "TNPeeaaFB7K9cmo4uQpcU32zGK8G1NYqeL"
  }
}

Plasma Stablecoin Funding

For Plasma wallet accounts, using a Plasma wallet as the funding source:

{
  "accountOrWalletInfo": {
    "accountType": "PLASMA_WALLET",
    "assetType": "USDT",
    "address": "0xAbCDEF1234567890aBCdEf1234567890ABcDef12"
  }
}

Polygon Stablecoin Funding

For Polygon wallet accounts, using a Polygon wallet as the funding source:

{
  "accountOrWalletInfo": {
    "accountType": "POLYGON_WALLET",
    "assetType": "USDC",
    "address": "0xAbCDEF1234567890aBCdEf1234567890ABcDef12"
  }
}

Base Stablecoin Funding

For Base wallet accounts, using a Base wallet as the funding source:

{
  "accountOrWalletInfo": {
    "accountType": "BASE_WALLET",
    "assetType": "USDC",
    "address": "0xAbCDEF1234567890aBCdEf1234567890ABcDef12"
  }
}

Checking account balances

The internal account balance reflects all deposits and withdrawals. The balance includes:

amount: The balance amount in the smallest currency unit (cents for USD, centavos for MXN/BRL, etc.)
currency: Full currency details including code, name, symbol, and decimal places

Example balance check

Fetch the balance of an internal account

curl -X GET 'https://api.lightspark.com/grid/2025-10-13/customers/internal-accounts?customerId=Customer:019542f5-b3e7-1d02-0000-000000000001&currency=USD' \
  -u "$GRID_CLIENT_ID:$GRID_CLIENT_SECRET"

Response

{
  "data": [
    {
      "id": "InternalAccount:e85dcbd6-dced-4ec4-b756-3c3a9ea3d965",
      "customerId": "Customer:019542f5-b3e7-1d02-0000-000000000001",
      "type": "INTERNAL_FIAT",
      "status": "ACTIVE",
      "balance": {
        "amount": 50000,
        "currency": {
          "code": "USD",
          "name": "United States Dollar",
          "symbol": "$",
          "decimals": 2
        }
      },
      "totalBalance": {
        "amount": 50000,
        "currency": {
          "code": "USD",
          "name": "United States Dollar",
          "symbol": "$",
          "decimals": 2
        }
      }
    }
  ],
  "hasMore": false,
  "totalCount": 1
}

Always check the decimals field in the currency object to correctly convert between display amounts and API amounts. For example, USD has 2 decimals, so an amount of 50000 represents $500.00.

Displaying funding instructions to customers

When customers need to deposit funds themselves, display the funding payment instructions in your application:

Retrieve the internal account

Fetch the customer’s internal account for their desired currency using the API.

Extract payment instructions

Parse the fundingPaymentInstructions array and select the appropriate instructions based on your customer’s preferred payment method.

const instructions = account.fundingPaymentInstructions[0];
const bankInfo = instructions.accountOrWalletInfo;

Display instructions clearly

Show the payment details prominently in your UI:

Account holder name
Bank name and routing information (account/routing number, CLABE, PIX key, etc.)
Reference code (if provided)
Any additional notes from instructionsNotes

The unique banking details in each internal account automatically route deposits to the correct destination.

Monitor for deposits

Set up webhook listeners to receive notifications when deposits are credited to the internal account. The account balance will update automatically.

You’ll receive INTERNAL_ACCOUNT.BALANCE_UPDATED webhook events when the internal account balance changes.

Best practices

Display complete funding instructions

Ensure your customers have all the information needed to make deposits. Consider implementing:

Clear display of all banking details from fundingPaymentInstructions
Copy-to-clipboard functionality for account numbers and reference codes
Email/SMS confirmations with complete deposit instructions

Monitor account balances proactively

Set up monitoring to alert customers when their balance is low:

if (account.balance.amount < minimumThreshold) {
  await notifyCustomer({
    type: 'LOW_BALANCE',
    account: account.id,
    instructions: account.fundingPaymentInstructions
  });
}

Handle multiple currencies efficiently

If your platform supports multiple currencies, organize internal accounts by currency in your UI:

const accountsByCurrency = accounts.data.reduce((acc, account) => {
  const code = account.balance.currency.code;
  acc[code] = account;
  return acc;
}, {});

// Quick lookup: accountsByCurrency['USD']

Cache account data appropriately

Internal account details (especially funding instructions) rarely change, so you can cache them safely. However, always fetch fresh balance data before initiating transfers.

Using internal accounts for ramps

Internal accounts play a critical role in both on-ramp and off-ramp flows:

For on-ramps (Fiat → Crypto)

Internal accounts are optional for on-ramp flows using just-in-time (JIT) funding:

JIT funding: Quotes provide payment instructions directly; funds flow through without requiring an internal account
Pre-funded model: Deposit fiat to internal account first, then create and execute conversion quotes

Most on-ramp implementations use JIT funding to avoid holding customer balances and simplify compliance.

For off-ramps (Crypto → Fiat)

Internal accounts are essential for off-ramp flows:

Deposit crypto: Transfer Bitcoin or stablecoins to the internal account
Hold balance: Crypto balance is held securely until conversion
Execute conversion: Create and execute quote to convert crypto to fiat and send to bank account

Off-ramps require pre-funded internal accounts with crypto balances. Grid supports Fiat, BTC, and Stablecoin deposits.

Crypto funding for internal accounts

For off-ramp operations, fund internal accounts with cryptocurrency:

Bitcoin (Lightning Network)

Internal accounts can receive Bitcoin via Lightning Network:

{
  "fundingPaymentInstructions": [
    {
      "accountType": "SPARK_WALLET",
      "assetType": "BTC",
      "address": "spark1pgssyuuuhnrrdjswal5c3s3rafw9w3y5dd4cjy3duxlf7hjzkp0rqx6dj6mrhu",
      "invoice": "lnbc15u1p3xnhl2pp5jptserfk3zk4qy42tlucycrfwxhydvlemu9pqr93tuzlv9cc7g3s..."
    }
  ]
}

Deposit methods:

Spark address: Reusable address for multiple deposits
Lightning invoice: Single-use invoice for specific amounts

Lightning Network transfers are typically instant and have minimal fees, making them ideal for crypto deposits.

Stablecoins

Internal accounts can also receive stablecoins via Lightning Network or Spark:

{
  "fundingPaymentInstructions": [
    {
      "accountType": "SPARK_WALLET",
      "assetType": "USDB",
      "address": "spark1pgssyuuuhnrrdjswal5c3s3rafw9w3y5dd4cjy3duxlf7hjzkp0rqx6dj6mrhu"
    }
  ]
}

Stablecoins like USDB are 1:1 pegged to USD, offering price stability for off-ramp balances while maintaining instant settlement via Lightning Network.

Multi-currency balances

Internal accounts support both fiat and crypto balances:

Example: Account with USD and BTC

{
  "data": [
    {
      "id": "InternalAccount:usd123",
      "customerId": "Customer:cust001",
      "balance": {
        "amount": 100000,
        "currency": {
          "code": "USD",
          "name": "United States Dollar",
          "symbol": "$",
          "decimals": 2
        }
      },
      "totalBalance": {
        "amount": 100000,
        "currency": {
          "code": "USD",
          "name": "United States Dollar",
          "symbol": "$",
          "decimals": 2
        }
      }
    },
    {
      "id": "InternalAccount:btc456",
      "customerId": "Customer:cust001",
      "balance": {
        "amount": 10000000,
        "currency": {
          "code": "BTC",
          "name": "Bitcoin",
          "symbol": "₿",
          "decimals": 8
        }
      },
      "totalBalance": {
        "amount": 10000000,
        "currency": {
          "code": "BTC",
          "name": "Bitcoin",
          "symbol": "₿",
          "decimals": 8
        }
      }
    }
  ]
}

Always check the decimals field when working with balances. USD uses 2 decimals (cents), while BTC uses 8 decimals (satoshis).

Monitoring account balance changes

Subscribe to INTERNAL_ACCOUNT.BALANCE_UPDATED webhooks to receive real-time balance updates:

{
  "id": "Webhook:019542f5-b3e7-1d02-0000-000000000007",
  "type": "INTERNAL_ACCOUNT.BALANCE_UPDATED",
  "timestamp": "2025-10-03T14:32:00Z",
  "data": {
    "id": "InternalAccount:btc456",
    "customerId": "Customer:019542f5-b3e7-1d02-0000-000000000001",
    "type": "INTERNAL_CRYPTO",
    "status": "ACTIVE",
    "balance": {
      "amount": 10000000,
      "currency": { "code": "BTC", "name": "Bitcoin", "symbol": "₿", "decimals": 8 }
    },
    "totalBalance": {
      "amount": 10000000,
      "currency": { "code": "BTC", "name": "Bitcoin", "symbol": "₿", "decimals": 8 }
    },
    "fundingPaymentInstructions": [],
    "createdAt": "2025-08-01T10:00:00Z",
    "updatedAt": "2025-10-03T14:32:00Z"
  }
}

Balance updates are triggered by: - Incoming deposits (fiat or crypto) - Quote executions (funds debited) - Failed transaction reversals (funds credited back)

Ramp-specific use cases

Pre-funding for off-ramps

Maintain crypto balances for instant fiat conversions:

// Check Bitcoin balance before off-ramp
const accounts = await getInternalAccounts(customerId);
const btcAccount = accounts.data.find(
  (acc) => acc.balance.currency.code === "BTC"
);

if (btcAccount.balance.amount >= requiredSats) {
  // Create quote to convert BTC to fiat
  const quote = await createQuote({
    source: { sourceType: "ACCOUNT", accountId: btcAccount.id },
    destination: { destinationType: "ACCOUNT", accountId: bankAccountId },
    lockedCurrencySide: "SENDING",
    lockedCurrencyAmount: requiredSats,
  });

  // Execute conversion
  await executeQuote(quote.id);
}

Platform treasury management

Use platform-level internal accounts for pooled liquidity:

# Get platform internal accounts
curl -X GET 'https://api.lightspark.com/grid/2025-10-13/platform/internal-accounts?currency=BTC' \
  -H 'Authorization: Basic $GRID_CLIENT_ID:$GRID_CLIENT_SECRET'

Platform internal accounts enable centralized treasury management for high-volume ramp operations.

Best practices for ramps

Choose the right funding model

On-ramps: Use JIT funding to avoid holding customer fiat
Off-ramps: Pre-fund with crypto for instant fiat conversions
High volume: Consider platform-level accounts for pooled liquidity

Monitor crypto price exposure

// Track BTC value in USD
const btcBalance = account.balance.amount; // satoshis
const currentRate = await getBtcUsdRate();
const usdValue = (btcBalance / 100000000) * currentRate;

if (usdValue > maxExposure) {
// Convert excess BTC to stablecoin
await convertToStablecoin(btcBalance - targetBalance);
}

Implement balance alerts

Set up proactive notifications for low balances:

// Alert when off-ramp liquidity is low
if (btcAccount.balance.amount < minimumSats) {
  await alertTreasury({
    type: 'LOW_CRYPTO_BALANCE',
    account: btcAccount.id,
    balance: btcAccount.balance.amount,
    minimumRequired: minimumSats
  });
}

Next steps

External Accounts - Configure destination accounts for conversions
Fiat-to-Crypto Conversion - Build conversion flows
Webhooks - Handle real-time notifications

Platform Configuration - Configure supported currencies
Sandbox Testing - Test funding and conversions safely
API Reference - Complete API documentation

Overview

Onboarding

Managing accounts

Conversion flows

Global Accounts

Platform tools

How internal accounts work

Retrieving internal accounts

List customer internal accounts

Filter by currency

List platform internal accounts

Understanding funding payment instructions

Checking account balances

Example balance check

Displaying funding instructions to customers

Best practices

Using internal accounts for ramps

For on-ramps (Fiat → Crypto)

For off-ramps (Crypto → Fiat)

Crypto funding for internal accounts

Bitcoin (Lightning Network)

Stablecoins

Multi-currency balances

Example: Account with USD and BTC

Monitoring account balance changes

Ramp-specific use cases

Pre-funding for off-ramps

Platform treasury management

Best practices for ramps

Next steps

​How internal accounts work

​Retrieving internal accounts

​List customer internal accounts

​Filter by currency

​List platform internal accounts

​Understanding funding payment instructions

​Checking account balances

​Example balance check

​Displaying funding instructions to customers

​Best practices

​Using internal accounts for ramps

​For on-ramps (Fiat → Crypto)

​For off-ramps (Crypto → Fiat)

​Crypto funding for internal accounts

​Bitcoin (Lightning Network)

​Stablecoins

​Multi-currency balances

​Example: Account with USD and BTC

​Monitoring account balance changes

​Ramp-specific use cases

​Pre-funding for off-ramps

​Platform treasury management

​Best practices for ramps

​Next steps

​Related resources

How internal accounts work

Retrieving internal accounts

List customer internal accounts

Filter by currency

List platform internal accounts

Understanding funding payment instructions

Checking account balances

Example balance check

Displaying funding instructions to customers

Best practices

Using internal accounts for ramps

For on-ramps (Fiat → Crypto)

For off-ramps (Crypto → Fiat)

Crypto funding for internal accounts

Bitcoin (Lightning Network)

Stablecoins

Multi-currency balances

Example: Account with USD and BTC

Monitoring account balance changes

Ramp-specific use cases

Pre-funding for off-ramps

Platform treasury management

Best practices for ramps

Next steps

Related resources