Backdated Transactions

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Overview

The effective_date feature is a critical functionality in financial systems that allows recording transactions with a financial date different from their system entry date.

This capability ensures seamless migration, accurate financial reporting, reconciliation, and historical balance calculations.

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Effective date vs created date

When effective_date isn’t specified, the system automatically uses the created date as the effective date.

• created_at: Timestamp of when the transaction was recorded in the system.
• effective_date: The actual financial date when the transaction occurred

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Create transaction with effective date

Call the Record Transaction endpoint:

POST http://YOUR_BLNK_INSTANCE_URL/transactions

{
  "amount": 358.90,
  "precision": 100,
  "reference": "unique_reference_1",
  "description": "Backdated transaction",
  "currency": "NGN",
  "source": "@source_account",
  "destination": "@destination_account",
  "effective_date": "2025-02-15T10:30:00Z"
}

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Balance calculations

In this section, you’ll learn how this affects how balances calculated.

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Current Running Balance

• Backdated transactions immediately update the current running balance.
• The running balance always reflects the most up-to-date financial position based on all known transactions.

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Example

• Current balance before backdated transaction: $500.
• Record a $200 transaction with an effective_date from last month.
• Current balance after: $700.

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Historical Balance Queries

When querying a balance at a specific point in time, the system:

1. Starts with the most recent snapshot before the requested time
2. Applies all transactions with an effective_date on or before the requested time
3. Ignores transactions with an effective_date after the requested time

{
  "balance_id": "bln_a03ef6af-1e5d-46a8-86a9-5fb1f2286f66",
  "balance": "1245.67",
  "credit_balance": "2000.00",
  "debit_balance": "754.33",
  "currency": "NGN",
  "timestamp": "2025-03-01T13:19:26Z"
}

In this example historical balance calculation includes:

• All transactions with effective_date on or before March 1st, 2025.
• Transactions recorded after March 1st are included if their effective date is on or before that date.

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Common use cases

Here are some use cases for backdating transactions:

1. Late-arriving transactions: Record transactions that occurred in the past but were discovered later, ensuring historical accuracy with backdated entries.
2. Month-end reconciliation: Attribute transactions to the correct fiscal period by backdating them, maintaining accurate financial records for period-end reporting.
3. Financial reporting: Generate precise reports for specific time periods by backdating transactions to reflect their true financial occurrence, improving data integrity.
4. Audit compliance: Maintain historically accurate records for auditing purposes by backdating transactions, ensuring compliance with regulatory requirements.
5. Error correction: Rectify mistakes or omissions in past records by backdating transactions to their original dates, preserving ledger accuracy. See also: Adjusting Balances →.
6. Historical analysis: Support retrospective financial analysis or trend tracking by backdating transactions, enabling accurate insights into past performance.

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Best practices & constraints

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Important Considerations

• Backdated transactions immediately impact the running balance.
• The effective_date:
  • Can be in the past.
  • Must not be in the future. Use scheduled_for instead to schedule transactions in the future. Learn how: Scheduling Transactions →.
  • Defaults to the current system time if not specified.

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Error Handling

Invalid effective date error:

{
  "error": "Invalid effective_date: must not be in the future",
  "status": 400
}

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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.

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