This guide explains common transaction scenarios and operational behaviors that may occur during card usage and payment processing.

It is intended to help clients better understand transaction flows, operational edge cases, and related handling mechanisms across different integration modes.

Forced Post Transaction (Merchant-Initiated Debit)

• Definition
  • Refers to transactions initiated by a merchant or platform without the cardholder's valid authorization, or beyond the originally agreed scope or authorization terms.
• Common Scenarios
  • A merchant continues charging after the user has cancelled a subscription by using previously saved payment details.
  • A hotel or car rental company charges additional amounts after the customer leaves, citing damages, penalties, or other fees.
  • A platform deducts the original transaction amount again after identifying abnormal refund behavior or suspected abuse.
  • A merchant retries a failed charge after the original payment could not be completed due to insufficient balance.
  • A platform or merchant initiates additional charges that the cardholder believes were not clearly disclosed or authorized in advance.
• Recommended Actions
  • Cardholders are advised to contact the merchant first to request clarification or a refund.
  • If the issue cannot be resolved directly with the merchant, Interlace may assist in initiating a chargeback dispute.

Unauthorized Transaction (Card Fraud)

• Definition
  • Refers to transactions where fraudsters illegally obtain and misuse a cardholder's payment card information (such as card number, expiry date, or CVV) to initiate transactions without the cardholder's permission.
• Recommended Actions
  • Freeze the Card Immediately: Use the Suspend Card API to freeze the card and prevent further fraudulent transactions.
  • Remove the Exposed Card: If sensitive card information has been exposed, use the Delete Card API to remove the card and and create a new one.
  • Configure Merchant Blacklists or Restrictions: Use the Consumption Scenarios API to configure custom MCC restrictions and block or restrict transactions from specific merchants or consumption scenarios. Only customer-configured restrictions are returned by the API; platform-level risk controls are not included.
  • Contact Interlace for Assistance: Provide suspicious transaction details to your account manager or operations team. Interlace may assist in initiating a chargeback dispute.
• Prevention Tips
  • Ensure proper system and integration security to reduce the risk of data leakage.
  • Advise cardholders to protect sensitive card information properly.
  • Avoid entering card details on unknown or untrusted websites.
  • Avoid clicking suspicious links or phishing pop-ups.

Negative Card Balance

• Definition
  • A negative balance occurs when the final debited amount exceeds the available card or budget balance, resulting in a balance below zero.
• Common Scenarios
  • A force post or additional merchant debit may exceed the available balance at settlement, resulting in a negative balance.
  • The authorized amount may match the available balance, but additional FX or cross-border fees may cause the final settlement amount to exceed the remaining balance.

• Negative Balance Monitoring
  • When a card or budget balance becomes negative due to transaction fees, exchange rate fluctuations, or other normal transaction scenarios, Interlace does not take immediate action. The balance can be restored by transferring sufficient funds to the affected card or budget.
  • You can monitor negative balances through the following webhook events and API:
    • CARD.BALANCE.NEGATIVE: Triggered when a card or budget balance changes from positive to negative.
    • List Cards with Negative Balance API: Retrieves cards and budgets with negative balances.
    • ACCOUNT.DAILY.NEGATIVE: Provides a daily account-level overview of outstanding negative balances.
• Scheduled Settlement
  • On the 1st and 15th of each month, Interlace checks negative card and budget balances from the previous cycle and sends a detailed report through the ACCOUNT.NEGATIVE.BILLING.DETAILS webhook event. You may manually settle the outstanding negative balances based on the report before automatic settlement.
  • On the 2nd and 16th of each month, Interlace automatically deducts funds from the applicable Infinity Account to settle any remaining negative balances and sends the ACCOUNT.NEGATIVE.CHARGE.BILLING.DETAILS webhook event with summaries and detailed reports for fully settled, partially settled, and unsettled balances.
• Force-Post Transactions
  • If a force-post transaction causes a card or budget balance to become negative, or occurs while the balance is already negative, Interlace automatically attempts to settle the negative balance from the applicable Infinity Account every two hours until it is fully settled. Once settled, the CARD.CHARGE webhook event and the corresponding transfer transaction notification will be sent.
• Operational Impact
  • Interlace automatically monitors and settles negative balances. You can track negative balances and settlement results through the related webhook events.
  • If the applicable Infinity Account has insufficient funds to cover all negative balances, withdrawals and Infinity Card operations, including card issuance and budget creation, will be temporarily restricted until all negative balances are fully settled. Deposits to the Infinity Account will remain available.
• Manual Repayment
  • To manually settle a negative balance, top up the applicable Infinity Account and transfer funds to the affected card or budget using the Prepaid Card Transfer In or Increase Budget Balance API. If not settled manually, Interlace will automatically deduct funds from the applicable Infinity Account according to the settlement process described below.
• Deduction Source by Integration Model

Transaction Adjustment

• Definition
  • When the authorized amount differs from the final settlement amount, Interlace performs a transaction adjustment to reflect the actual settled amount. This commonly occurs in scenarios such as hotels, gas stations, and restaurants, where the final settlement amount may differ from the original authorization amount.
• Common Scenarios
  • Final settlement amount exceeds the authorized amount: A hotel pre-authorizes $200, but the final settlement amount is $280 after checkout. An additional adjustment transaction of $80 will be generated.
  • Final settlement amount is lower than the authorized amount: A restaurant pre-authorizes $100 including an estimated tip, but the final settlement amount is $80. A refund adjustment transaction of $20 will be generated.
• Adjustment Webhook Events
  • Settlement Amount < Authorized Amount
    1. Example: Authorized $100, final settlement $50. The remaining $50 is returned through a refund adjustment transaction.
    2. Original transaction created: CARD_TRANSACTION.CREATED type: 1-Consumption status: PENDING
    3. Refund adjustment transaction generated: CARD_TRANSACTION.UPDATED type: 0-Credit status: CLOSED relatedCardTransactionId references the original transaction businessCodeList includes 1105
    4. Original transaction settled: CARD_TRANSACTION.UPDATED type: 1-Consumption status: CLOSED businessCodeList includes 1005
  • Settlement Amount > Authorized Amount
    1. Example: Authorized $100, final settlement $150. An additional adjustment transaction of $50 will be generated.
    2. Original transaction created: CARD_TRANSACTION.CREATED type: 1-Consumption status: PENDING
    3. Additional consumption adjustment transaction generated: CARD_TRANSACTION.UPDATED type: 1-Consumption status: CLOSED relatedCardTransactionId references the original transaction businessCodeList includes 1103
    4. Original transaction settled: CARD_TRANSACTION.UPDATED type: 1-Consumption status: CLOSED businessCodeList includes 1003
  • Reference
    • For detailed business code definitions, refer to the Business Code Reference Guide.