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REASON CODE GUIDE · DISCOVER

Discover UA02: Fraudulent Transaction – Card Absent Defense Playbook

Discover’s CNP fraud code has a pre-dispute inquiry phase that most merchants ignore — and it’s your best opportunity to resolve the dispute before it becomes a formal chargeback.

Inquiry Window
~20 Days
Pre-dispute phase — respond immediately
Dispute Window
30 Days
From formal dispute notice
Network
Discover
Closed-loop network
Category
Fraud
CNP unauthorized use
Key Advantage
Inquiry Phase
Pre-chargeback resolution opportunity
OVERVIEW

What This Dispute Means

Discover UA02 is Discover’s card-not-present fraud dispute code, equivalent to Visa 10.4, Mastercard 4837, and Amex F29. It is filed when a cardholder disputes a card-not-present transaction as fraudulent — claiming they did not authorize the charge and that someone else used their card information without their knowledge.

Like American Express, Discover acts as both the issuer (the cardholder’s bank) and the acquirer (the merchant’s bank) for Discover-branded cards. This closed-loop structure means Discover controls the adjudication process internally — similar to Amex, the dispute is reviewed by the same company that issued the card to the cardholder.

One structural feature distinguishes Discover UA02 from every other major network’s CNP fraud code: the pre-dispute inquiry phase. Before many Discover disputes escalate to a formal chargeback, Discover sends the merchant an inquiry — a request for transaction documentation. This inquiry phase is your first and often best opportunity to resolve the dispute before it becomes a formal chargeback with associated fees and win-rate impact. Most merchants miss it entirely.

Discover's Two-Phase Process

Phase What It Is Strategic Priority
Phase 1: Inquiry Discover requests transaction documentation before issuing a formal chargeback. Typically arrives within a few days of the cardholder reporting the dispute. HIGHEST — resolve here to avoid a formal chargeback entirely
Phase 2: Formal Dispute If the inquiry response is insufficient or ignored, Discover issues a formal chargeback. 30-day response window from the formal dispute notice. HIGH — full evidence package required, reviewed internally by Discover
EVIDENCE REQUIREMENTS

Required Evidence

Whether you are responding to an inquiry or a formal dispute, the same core evidence package applies. Build your full evidence package for every dispute — do not wait to see whether an inquiry escalates before gathering documentation. These three categories form the foundation of every UA02 response.

#1 — Transaction authorization data

Discover uses the term CID (Card Identification Number) for the security code, consistent with Amex terminology — not CVV or CVC. This is the 3-digit security code on the back of Discover cards (Discover uses CID on the back, unlike Amex which uses 4 digits on the front).

Data Point What to Submit
Authorization Approval Code The authorization code from the transaction response, confirming Discover approved the charge at the time it was processed.
CID Verification Result Discover's CID verification result. Include the raw result code and its interpretation. A CID match is strong evidence the cardholder had the physical card (or the security code).
AVS Result Address Verification System result showing whether the billing address entered at checkout matched the card on file. Include the full result code.

#2 — Device and identity evidence

The core identity evidence in any CNP fraud dispute — data linking the transaction session to the cardholder's known identity.

Evidence Type What to Submit
IP Address & Geolocation The IP address of the session that placed the order, with geolocation data. Compare to the cardholder's billing address region and to prior authenticated sessions on the same account.
Device Fingerprint / Device ID A device or browser fingerprint from the transaction session. If this matches prior sessions on the same account, include that history — it establishes a pattern of legitimate device use.
Account Creation Date The date the account was created — must predate the disputed transaction. A long-standing account with consistent profile data is inconsistent with unauthorized use.

#3 — Order and behavioral evidence

Evidence Type What to Submit
Prior Purchase History Records showing prior orders on the same account without disputes. A history of purchases from the same device or account undermines a claim of total non-authorization.
Customer Communications Order confirmation email delivery and open records. Any post-purchase communication — support inquiry, shipping question — that implies awareness of the transaction.
Post-Transaction Activity Account logins, product downloads, content access, or any platform activity after the transaction date. Post-purchase product engagement is strong evidence of cardholder involvement.
INQUIRY PHASE STRATEGY

The Inquiry Phase: Your Best Opportunity

The inquiry phase is the defining feature of Discover’s dispute process and the single greatest advantage Discover merchants have over merchants on other networks. Use it aggressively.

KEY INSIGHT

Many Discover disputes start as inquiries before becoming formal chargebacks. Respond to every inquiry with your full evidence package — a well-documented inquiry response often closes the dispute before it costs you a chargeback fee or impacts your dispute rate.

#4 — Inquiry response strategy

Action Why It Matters
Respond immediately The inquiry window is typically shorter than the formal dispute window. The moment you receive an inquiry notification, begin assembling your full evidence package — do not triage it as lower priority than formal disputes.
Submit your complete evidence package For inquiry responses, submit everything — not a partial package. If you provide a thin response at inquiry and it fails, you may not get another opportunity before the dispute escalates to a formal chargeback.
Address the cardholder's claim directly Discover's inquiry notification includes the cardholder's stated concern. Address it directly in your inquiry response — do not submit generic authorization data without connecting it to the cardholder's specific claim.

#5 — Usage and access logs for digital products

  • For software or SaaS: login session logs with timestamps and IP addresses after the purchase date.
  • For digital downloads: download records with file size, date, and download IP address.
  • For content or streaming: view count, playback records, or reading history dated after the transaction.
  • Any feature interaction showing the purchased product was actively used after the charge.

#6 — No pre-dispute fraud contact

  • Export your support records, CRM, and email history showing no report of unauthorized card use was received from the cardholder before the inquiry or dispute was filed.
  • A cardholder who "discovered fraud" but did not report it to the merchant first is a signal of friendly fraud — note the absence of any fraud report in your response.

Supporting Evidence

These items reinforce your case and become important if the formal dispute phase is reached.

#7 — Product and delivery documentation

  • Order confirmation showing what was purchased and when.
  • For physical goods: carrier tracking and delivery confirmation to the cardholder-provided address.
  • For subscriptions: the original recurring billing authorization showing the cardholder's consent to ongoing charges.
  • Signed terms of service or checkout consent confirming the cardholder agreed to purchase terms.

#8 — Fraud tool and risk signal outputs

  • Risk assessment from your fraud screening tool showing the transaction was flagged as low-risk at authorization.
  • Any positive identity verification results from your checkout process.
  • Address validation output confirming the billing address was verified before fulfillment.
WHAT TO AVOID

Critical Mistakes

These are the most common reasons Discover UA02 disputes are lost — most involving the inquiry phase being handled incorrectly or ignored entirely.

Mistake #1: Ignoring the inquiry phase

This is the single most costly mistake Discover merchants make. The inquiry is Discover's pre-chargeback signal that a dispute is being considered. Merchants who ignore inquiries or treat them as low-priority consistently receive formal chargebacks that could have been prevented — with an associated fee and dispute rate impact that a successful inquiry response would have avoided.

What to do instead

Build Discover inquiry responses into your standard dispute workflow with the same urgency as formal chargebacks. The moment an inquiry arrives, assign it, begin evidence collection, and target a response within the first week. Do not wait to see if it escalates — respond immediately with your full evidence package.

Mistake #2: Submitting a partial evidence package at inquiry

Some merchants respond to inquiries with a minimal package — just a tracking number or a basic authorization record — planning to supplement if the dispute escalates to formal. This almost always backfires. If the inquiry closes without resolution due to insufficient evidence, you may not have another opportunity before the formal chargeback window runs or the case is ruled without your input.

What to do instead

Treat every inquiry as if it is your only opportunity to prevent the chargeback. Build the complete evidence package — authorization data, device and IP, account history, post-transaction activity — and submit everything at inquiry. The investment of 30–45 minutes is justified by the chargeback prevention.

Mistake #3: Using the wrong submission channel

Discover has a specific merchant dispute portal. Submitting responses outside the designated channel — by fax, email, or through a third-party processor without proper Discover routing — can result in the response not being received or processed, leading to an automatic loss regardless of evidence quality.

What to do instead

Log in to Discover's merchant dispute portal or your processor's Discover-specific dispute interface. Confirm the submission channel with your acquirer if you are unsure. After submitting, save the confirmation receipt with timestamp as proof of timely submission.

Mistake #4: Treating Discover disputes like Visa or Mastercard disputes

The inquiry phase is unique to Discover among major networks. Merchants who import their Visa/Mastercard representment workflow directly into Discover dispute handling miss this phase entirely — and submit formal dispute responses that are structurally correct but arrived at the wrong stage or through the wrong process.

What to do instead

Create a Discover-specific dispute workflow that begins at the inquiry phase. The inquiry and formal dispute require different submissions to different portal sections — map out both steps before your first Discover dispute arrives, not during it.

Mistake #5: Missing the inquiry response window

The inquiry window is shorter than the formal dispute window, and its deadline is not always clearly labeled in the notification. Merchants who receive an inquiry notification, flag it for review, and return to it a week later often discover they have missed the inquiry window — and the dispute has automatically escalated to a formal chargeback.

What to do instead

Set an immediate alert for the inquiry response deadline the day you receive the notification. Act within 48 hours. Do not rely on the notification language to clearly state the deadline — check your Discover portal for the applicable timeline and set a calendar alert accordingly.

RESPONSE FRAMEWORK

Winning Response Framework

The framework below applies to both inquiry responses and formal dispute rebuttals. For inquiry responses, use this as your template and submit through Discover’s inquiry portal. For formal disputes, adapt it to Discover’s rebuttal form fields.

Step 1 — Identify the dispute and phase clearly

Template Language
DISCOVER UA02 RESPONSE Case Reference: [DISCOVER DISPUTE/INQUIRY ID] Phase: INQUIRY / FORMAL DISPUTE [select one] Merchant: [YOUR BUSINESS NAME] Transaction Date: [DATE] Transaction Amount: [AMOUNT] Cardholder: [LAST 4 DIGITS ONLY] We are responding to the above [inquiry / dispute] regarding this transaction. Please find our complete evidence below.

Step 2 — Summarize your case explicitly

State the facts of the authorization and identity evidence in plain language before presenting the exhibits. Address the cardholder's specific stated claim directly — do not make the reviewer infer authorization from raw data.

Template Language
SECTION 1 — TRANSACTION AUTHORIZATION Authorization Approval Code: [CODE] Authorization Date/Time: [DATE TIME UTC] AVS Result: [FULL MATCH / PARTIAL / NO MATCH] CID Verification Result: MATCH / NO MATCH / NOT COLLECTED SECTION 2 — CARDHOLDER IDENTITY EVIDENCE Account Created: [DATE — must predate transaction] Prior Orders on This Card: [NUMBER] prior transactions, [NUMBER] months of history No Prior Disputes: [YES/NO] Billing Address Match: [YES/NO] Email on File: [MASKED EMAIL] IP Address at Checkout: [IP] Geolocation: [CITY, STATE/COUNTRY] Device Fingerprint/ID: [ID or hash — from payment processor logs] SECTION 3 — POST-TRANSACTION EVIDENCE Order Confirmation Sent: [DATE/TIME] Confirmation Email Opened: [YES/NO — from email delivery logs] [For digital goods] Access Logs: First accessed [DATE/TIME], [N] sessions recorded [For physical goods] Shipping Confirmation: Tracking [NUMBER], delivered [DATE] Customer Communications: [Summary of any post-purchase contact] SECTION 4 — RESPONSE TO DISPUTE CLAIM Claim: Cardholder states they did not authorize this transaction. Response: The transaction was processed with a valid CID and AVS match, from an IP address in [GEOLOCATION] consistent with the cardholder's account profile. The customer account was created [DATE], [X] months prior to this transaction. [NUMBER] prior purchases have been made on this account without dispute. [For digital goods: The product was accessed [N] times following the charge.] The cardholder did not contact us prior to this [inquiry / dispute] to report unauthorized account access. SECTION 5 — ATTACHED DOCUMENTATION [ ] Authorization and CID/AVS verification record [ ] IP address and geolocation report [ ] Account creation and order history [ ] Device fingerprint and prior session log [ ] Post-transaction communications or delivery confirmation [ ] Usage/access logs (digital goods) or shipping proof

Step 3 — Sequence your evidence by strength

Priority Evidence Type
First Authorization approval code and CID verification result.
Second Device fingerprint and IP geolocation, linked to prior authenticated sessions.
Third Post-transaction activity — account logins, product access, email engagement after the charge date.
Last Account creation history, prior transaction records, AVS result, order confirmation details.

Step 4 — Label and explain each exhibit

For both inquiry and formal dispute responses, label each attached document clearly and reference it by exhibit number in your response sections. Discover reviewers match exhibit references in the response text to attached files — unlabeled or unreferenced exhibits may not be reviewed.

Template Language
Exhibit 1: Authorization and CID/AVS Verification Record Payment processor record for transaction [ID] showing authorization approval code [CODE], CID result: MATCH, AVS result: FULL MATCH. Downloaded from [PROCESSOR] portal on [DATE].

Real-World Examples

✓ Winning Example — E-learning Platform (Inquiry Phase)

The situation: $195 annual e-learning subscription. Discover sent a UA02 inquiry after the cardholder reported the charge as unauthorized. The merchant responded at the inquiry phase — the dispute never became a formal chargeback.

Opening statement submitted at inquiry:

Inquiry Response Opening
"The transaction was authorized with a passing CID result and full AVS match. The order was placed from IP 45.33.91.22, which geolocates to Seattle, WA — within 8 miles of the cardholder's billing zip code. The device fingerprint from this session matches 4 prior authenticated sessions on this account, going back 9 months. Following the subscription purchase, the cardholder logged in 6 times and completed 3 course modules over the following 12 days. The account was created 9 months before this charge. The cardholder did not contact us prior to this inquiry to report any unauthorized access."

Evidence provided:

Exhibit Evidence
1 Processor record: CID MATCH, AVS FULL MATCH, Authorization Code: 93K714. Downloaded from Stripe dashboard with transaction timestamp.
2 IP geolocation: 45.33.91.22 → Seattle, WA. Device fingerprint D-29581 matching 4 prior sessions across 9 months, with session dates and IP ranges.
3 LMS activity log: 6 login sessions with timestamps and IP addresses, 3 course modules completed with timestamps — all occurring 1–12 days after the disputed charge.
4 Account creation record: 9 months prior to disputed transaction. Prior purchase history: 1 prior annual subscription renewal, no disputes. CRM export showing zero fraud reports before inquiry.

Result: Discover closed the inquiry in the merchant's favor. No formal chargeback was issued.

Why it worked at the inquiry phase:

  • Responding at inquiry with a complete evidence package resolved the dispute before it became a formal chargeback — saving the chargeback fee and protecting the dispute rate
  • CID match and full AVS match directly addressed Discover's authorization requirements at the highest level of confidence
  • 6 post-purchase logins and 3 completed course modules made the "I didn't authorize this" claim implausible — the cardholder actively engaged with the product after the charge
  • Device fingerprint matching 9 months of prior sessions established a long-standing legitimate account relationship
✗ Losing Example — Software Store

The situation: $89 software license. Discover sent a UA02 inquiry. The merchant ignored it. The dispute escalated to a formal chargeback. At the formal chargeback stage, they submitted a generic response.

What they submitted at formal dispute:

Response Submitted
"We dispute this chargeback. The order was placed on our website and our payment processor approved the transaction. The software was delivered to the email address provided. We have been selling software online since 2018. Please find the order confirmation attached."

Result: Dispute ruled in cardholder's favor.

Why it lost:

Mistake Explanation
Inquiry ignored entirely The best opportunity to resolve the dispute — at zero chargeback fee — was missed. The dispute escalated automatically because no inquiry response was submitted.
No CID or AVS result No authorization verification data was included. "Our processor approved the transaction" is not a substitute for the actual CID result or approval code.
No device or IP data The identity evidence — who was behind the keyboard — was entirely absent. The response had no way to connect the order session to the cardholder.
Email delivery as authorization evidence Proving the software was delivered to the email on file does not prove the cardholder authorized the purchase or accessed the software. UA02 is an authorization dispute, not a delivery dispute.

What they should have submitted:

  • Full inquiry response at the inquiry phase — any evidence at that stage might have prevented the formal dispute entirely
  • CID verification result and authorization code from the payment processor
  • IP address with geolocation and device fingerprint from the checkout session
  • Software download or activation log showing the cardholder used the product after the charge
  • Account creation history and prior purchase records establishing a legitimate account relationship

Before You Submit

Run through this checklist for both inquiry responses and formal dispute rebuttals.

Authorization data

  • Authorization approval code included
  • CID verification result included — "MATCH" / "NO MATCH" / "NOT COLLECTED" stated explicitly
  • AVS result code included
  • All authorization data mapped to Discover's form fields if submitting a formal dispute

Device and identity evidence

  • IP address and geolocation of checkout session included
  • Device fingerprint or device ID included
  • Prior sessions from the same device documented with dates
  • Account creation date predating the transaction included

Discover-specific process compliance

  • Phase identified clearly: INQUIRY or FORMAL DISPUTE
  • Submitted through Discover's merchant portal — not by fax or third-party email
  • Cardholder's stated dispute reason addressed directly
  • Submission confirmation saved with timestamp
  • Response submitted within the inquiry window — or within 30 days of formal dispute notice

Post-transaction behavioral evidence

  • Account logins or product access after the charge date included
  • For digital goods: download logs or usage records with timestamps
  • For physical goods: carrier delivery confirmation to cardholder-provided address
  • Order confirmation email open records included
  • CRM export confirming no pre-dispute fraud report received from the cardholder

Proactive Prevention

These steps reduce your UA02 exposure and ensure you are prepared for both the inquiry phase and any escalation to a formal dispute.

Action Why It Matters
Build a Discover-specific inquiry workflow Discover inquiries require immediate action. Create a workflow that identifies Discover inquiries on arrival, assigns an owner within the day, and targets a response within 5–7 days. Most inquiry opportunities are missed because they are treated like lower-priority tickets.
Always collect CID at checkout Discover's CID is the 3-digit security code on the back of the card. Collecting and verifying CID at checkout — and storing the verification result — is your most impactful single preparation for UA02 disputes. A CID match is decisive evidence at both the inquiry and formal dispute phase.
Capture device fingerprints and IP at every transaction This data must be captured at the moment of authorization — it cannot be reconstructed afterward. Implement a fraud tool or processor feature that archives device ID and IP with every transaction record.
Log post-purchase activity continuously Session logs, downloads, and feature usage with timestamps are your strongest evidence that the cardholder was involved with the product after the charge. This data is automatically generated — ensure it is retained and accessible for dispute resolution.
Send order confirmations with delivery tracking Immediate order confirmations that the cardholder opens create a documented touchpoint. For physical goods, delivery notifications with tracking links that the customer clicks prove awareness of the shipment and undermine non-receipt claims that often accompany fraud disputes.
About This Guide

This playbook is updated at least twice annually to reflect changes in Discover's dispute rules and processes. Document Version: 2026.1 · Last Updated: March 2026 · Covers: Discover UA02 / Fraudulent Transaction — Card Absent

RELATED GUIDES

Related Reason Code Guides

UA02 is the Discover equivalent of CNP fraud codes across all four major networks. The evidence requirements overlap significantly — these guides cover the same dispute category with their network-specific differences:

AMERICAN EXPRESS
Amex F29: Card Not Present Fraud
VISA
Visa 10.4: Other Fraud – Card Absent
MASTERCARD
Mastercard 4837: No Cardholder Authorization