Disputes Best Practices

Disputes inconvenience you and your customers, so the best strategy is to avoid them. Once the bank issues a dispute, you must follow the full process; refunds are no longer possible. Also, remember that both Omise and the credit card networks closely monitor dispute rates, and high dispute rates can lead to penalties and contract termination. Merchants with a dispute rate above 0.3% may be asked to reduce it.

Disputes are divided into two categories: Commercial disputes, where the customer is unhappy with the service provided or goods received, and fraud, where the cardholder did not approve the charge.

Not sure where to start? Here's the fastest way to find what you need:

• Just received a dispute? Jump to your specific flow: commercial dispute, fraud dispute without 3DS, or fraud dispute with 3DS.
• Want to reduce your dispute rate? See tips to minimize commercial disputes or tips to minimize fraud disputes.
• Need to know what evidence to gather? See evidence for commercial disputes.
• Want to manage disputes via code? See the Disputes API.

🕒 Dispute timeline at a glance

🤝 Commercial disputes

Omise provides a portal to upload evidence to decline any disputes received; you may also accept the dispute. You can also manage disputes programmatically using the Disputes API. For declined disputes, the issuer bank decides whether to pursue the case further. They will likely do so if the evidence is unclear or does not support the case well enough. If you open a second dispute, you can accept it again or initiate arbitration with the card brand, which costs between USD 500 and USD 750 if you lose (however, Omise deducts the fee upfront).

You decide whether the dispute is justified. If you have your customers' contact details, it's best to reach out as soon as possible. Disputes often arise from misunderstandings or unrecognized charges. A message from the customer acknowledging the misunderstanding can be used as evidence and help you win the case. Asking the customer to contact their bank directly is the easiest and quickest way to resolve a dispute.

Cardholder authentication (3DS) does not protect from commercial disputes.

How a commercial dispute plays out, step by step

1. Within 120 days of when the customer should have received the goods or service, the customer disputes the transaction with their bank.
2. The bank forwards the dispute to Omise.
3. Omise deducts the disputed amount from the merchant's balance and forwards the dispute to the merchant.
4. The merchant has 7 days to respond by accepting or declining the dispute.
5. If the merchant declines and submits evidence, Omise forwards that decision to the bank.
6. If the bank finds the evidence sufficient, the dispute is marked as won, and the disputed amount is credited back to the merchant's balance.
7. If the bank doesn't find the evidence sufficient, it can open a second dispute within its 45-to-90-day window, and Omise forwards it to the merchant as well.
8. The merchant has 7 days to either accept the second dispute or request arbitration.
9. If the merchant accepts the first or second dispute at any stage — or doesn't respond within the applicable window — the dispute is marked as lost.

Tips to minimize commercial disputes

• Provide clear details of your product or service so customers know what to expect.

• Provide communication channels so you can handle inquiries promptly. Share contact information prominently on your website.

• Be generous with your customers. If a customer is unhappy with their purchase and wants to reject the payment, try to resolve the issue first with a return, refund, or other option.

• Make return and refund policies clear and visible during checkout; otherwise, banks and card brands may assume you provide a full refund upon request.

• Document all interactions with customers. Have a signed receipt (physical goods) or a download or access log (digital goods) associated with the customer.

Evidence for commercial disputes

To resolve disputes, providing information that proves the charge was legitimate and that the goods/services have been successfully delivered to the client usually results in the merchant winning the case. Failing to provide such evidence, or having the charge proven fraudulent, usually results in the merchant losing the case.

Evidence for physical goods disputes

• Cardholder details: name and shipping address
• Details of purchase: list of products purchased
• How and where the purchase was made: merchant name and store URL
• Proof that the product was received or used by the cardholder

Submit this evidence via the dispute portal in your dashboard or the Disputes API.

Evidence for digital goods disputes

• Cardholder details: name and shipping address
• Details of purchase: list of products purchased
• How and where the purchase was made: merchant name and store URL
• Any log showing that the customer accessed the website or application on or after the charge date
• Any log showing that the product was downloaded or received by the customer, including the date and time it was downloaded

Submit this evidence via the dispute portal in your dashboard or the Disputes API.

Evidence for service disputes

• Cardholder details: name and shipping address
• Details of purchase: list of services purchased
• How and where the purchase was made: merchant name and store URL
• Proof that the service has been provided to the cardholder

Submit this evidence via the dispute portal in your dashboard or the Disputes API.

Omise recommends submitting all evidence with an English translation, if necessary. An English translation is required for the arbitration stage, where the card brand's dispute committee (Visa, Mastercard, JCB) will be involved.

🚨 Fraud disputes

The process differs depending on whether the original charge was authenticated with 3DS — see fraud disputes without 3DS or fraud disputes with 3DS.

Fraud disputes without 3DS authentication

For fraud disputes that were not authenticated with 3DS, the merchant is liable for any dispute. It is improbable that any evidence provided will be accepted by the issuer or in arbitration. Declining the dispute — even with evidence attached — effectively means accepting that arbitration will follow, since evidence is unlikely to change the outcome. The arbitration fee is deducted immediately in this case.

How a fraud dispute without 3DS plays out, step by step

1. Within 120 days of capture, the customer disputes the transaction with their bank as fraudulent.
2. The bank forwards the dispute to Omise.
3. Omise deducts the disputed amount from the merchant's balance and forwards the dispute to the merchant.
4. The merchant has 7 days to respond.
5. If the merchant declines and submits evidence, this is treated as effectively accepting that arbitration will follow, since evidence rarely changes the outcome for an unauthenticated fraud dispute. Omise deducts the arbitration fee immediately and forwards the decline decision to the bank.
6. If the bank still isn't satisfied within its 45-to-90-day window, it informs Omise that the arbitration process is proceeding.
7. If the merchant doesn't decline the dispute, it's marked as lost.

Fraud disputes with 3DS authentication

Usually, the issuer should not create fraud disputes for charges with successful cardholder authentication (3DS). Visa does not allow it in their system, and Mastercard does not allow it in their policy. However, some banks still do, and Omise must follow the process. Even with 3DS, charges can still be fraudulent, mainly because banks may not implement 3DS securely or because the bank’s 3DS authentication server is offline. Therefore, it is still essential to monitor such charges and block or prevent the likely fraudulent ones.

Omise allows you to provide additional evidence for such disputes. However, Omise will take action and submit a dispute decline decision on your behalf using the successful 3DS authentication as evidence. In very rare cases, issuer banks issue a second dispute. In this case, it is up to you to decide if you want to go to arbitration.

How a fraud dispute with 3DS plays out, step by step

1. Within 120 days of capture, the customer disputes the transaction with their bank.
2. The bank forwards the dispute to Omise.
3. Omise deducts the disputed amount from the merchant's balance and forwards the dispute to the merchant.
4. The merchant has 7 days to provide additional evidence optionally.
5. Omise submits the successful 3DS authentication to the bank as evidence on the merchant's behalf.
6. If the bank accepts the 3DS evidence, the dispute is marked as won, and the disputed amount is credited back to the merchant's balance.
7. If the bank doesn't accept the 3DS evidence, it can open a second dispute within its 45-to-90-day window, which Omise forwards to the merchant.
8. The merchant has 7 days to either accept the second dispute or request arbitration.
9. If the merchant accepts the second dispute — or doesn't respond within the window — the dispute is marked as lost.

Tips to minimize fraud disputes

• Refund early if you see a suspicious charge, contact the customer, and refund if you believe it was fraudulent.
• Send additional information to improve Omise's ability to perform real-time fraud protection and charge pattern analysis.
  • When creating a token, provide the billing address.
  • When creating a charge, provide the customer's actual IP address using the ip parameter and the product/service name, number of items, or estimated delivery time using the description parameter.
  • When creating a customer, provide the customer's name, email, and phone number using the name, email, and description parameters.
• Use Dynamic 3DS (if available) to ensure low-value charges don't require additional authentication, while higher-value ones (e.g., a total value larger than THB 10,000) do. Dynamic 3DS also allows Omise to require 3DS for suspicious or risky charges.
• Set charge limits that make sense for your business. You can ask Omise to configure account-specific charge limits — for example, a maximum per-charge limit if you don't expect any single purchase to exceed THB 20,000, or a limit on how many charges a cardholder can make per hour or day.

❓ FAQ

Is 3DS available for merchants registered in Japan? 🚫 No — 3DS is not supported for accounts registered in Japan.

Does 3DS protect against commercial disputes? 🚫 No. Cardholder authentication (3DS) only addresses fraud disputes (where the cardholder claims they didn't authorize the charge) — it doesn't protect against commercial disputes (where the customer is unhappy with the goods or service itself).

What's the easiest way to resolve a commercial dispute? Contacting the customer directly and asking them to contact their bank — this is the fastest way to resolve a dispute, since disputes often arise from misunderstandings or unrecognized charges that a quick conversation can clear up.

Is the 7-day response window the same for commercial and fraud disputes? Yes. Whether it's a commercial dispute, a fraud dispute without 3DS, or a fraud dispute with 3DS, the merchant has 7 days to respond at each stage.

What happens if I don't respond to a dispute within the response window? Not responding is treated the same as accepting the dispute, and it's marked as lost.

When is the arbitration fee charged? Upfront, as soon as arbitration is requested — not only if the dispute is ultimately lost.

What language should dispute evidence be submitted in? English is recommended for all evidence, and required at the arbitration stage, where the card brand's dispute committee (Visa, Mastercard, JCB) is involved.

What dispute rate triggers action from Omise? 📌 Above 0.3% — merchants with a dispute rate above 0.3% may be asked to find ways to reduce it.

What happens if my dispute rate stays too high? Both Omise and the credit card networks monitor dispute rates closely, and high rates can lead to penalties or contract termination.

What information should I provide to help prevent fraud disputes? Provide the billing address when creating a token; the customer's IP address (ip parameter) and a description of the product/service, item count, or delivery time (description parameter) when creating a charge; and the customer's name, email, and phone number when creating a customer. This additional information improves Omise's real-time fraud protection and charge pattern analysis.

What is Dynamic 3DS? A feature that applies 3DS selectively based on risk: low-value charges won't require the customer to complete additional authentication, while higher-value ones (for example, over THB 10,000) will. It also lets Omise require 3DS for suspicious or risky charges regardless of amount.

Can I set custom charge limits for my account? Yes. You can ask Omise to configure account-specific charge limits—for example, a maximum per-charge amount or a limit on how many charges a single cardholder can make per hour or day.

👉 Related content

• Disputes Overview
• Disputes API
• 3D Secure
• Charges API