Chargeback Reason Codes Explained for E-Commerce Teams, The Few That Drive Most Losses

Jan 31, 2026

A chargeback can feel like a random punch to revenue. One day it’s a “fraud” claim, the next it’s “item not received,” and suddenly your team is stuck in a loop of screenshots, tracking links, and portal deadlines.

That’s why chargeback reason codes matter. They’re the short labels banks and card networks use to explain why the money got pulled back. If you treat them like “just admin,” you miss what they’re really saying: where your checkout, fulfillment, product promise, or refund process is leaking.

The good news is most losses don’t come from dozens of unique issues. A small set of code categories tends to drive the bulk of e-commerce pain, and once you identify your top two or three, the fixes get a lot clearer.

What chargeback reason codes really tell you (and what they don’t)

Think of a reason code like a shipping label on a dispute. It tells you where the bank is routing the case, not the full story of what happened. Two customers can file the same “fraud” code for totally different reasons, one used a stolen card, the other forgot the purchase and panicked when the descriptor looked unfamiliar.

Reason codes also aren’t perfectly consistent across card networks. Visa and Mastercard have different numbering, and processors often group them into categories (fraud, product not received, product unacceptable, credit not processed, and so on). If you want a clean mental model, start with how processors categorize disputes, then map the network codes you see most often into those buckets. Stripe’s overview of dispute reason code categories is a helpful reference for how those buckets typically get organized.

For an e-commerce team, the real value comes from adding two internal fields to every dispute record:

• What actually triggered this (late carrier scan, variant confusion, subscription cancel failed, refund took too long)
• What proof would have prevented it (delivery confirmation, product page clarity, cancellation logs, refund timestamp)

Over time, you stop seeing a pile of “chargebacks.” You start seeing patterns, like “90 percent of our losses are delivery claims on untracked shipments” or “most fraud disputes happen on first-time orders with express shipping.”

One more point that saves time: reason codes are tightly linked to evidence rules. Networks spell out what counts as “compelling evidence,” and it varies by scenario. Mastercard’s official Chargeback Guide (Merchant Edition) is dense, but it makes one thing obvious: winning is less about arguing and more about matching the exact evidence type the code calls for.

The few reason code buckets that usually drive the biggest losses

If you look at dispute logs across most online sellers, the same buckets show up again and again. The labels differ, but the story is familiar.

Here’s a practical cheat sheet e-commerce teams can use to focus on what typically causes the most damage:

A few blunt truths sit underneath these buckets:

“Fraud” doesn’t always mean stolen cards. It can be a real customer who didn’t recognize the charge, couldn’t reach support, or didn’t like the return policy. That’s why billing descriptors, receipts, and fast support are part of fraud prevention.

“Not received” is often a process problem, not a carrier problem. Late dispatch, partial shipments, missing apartment numbers, and weak handoff scans all lead to the same outcome: the bank sees uncertainty, and uncertainty costs you.

“Not as described” is where marketing meets operations. If your photos are too edited, variant labels are confusing, or sizing is vague, that dispute bucket grows quietly until it’s a monthly tax.

A reason-code playbook e-commerce teams can run every week

Most teams don’t need a new “chargebacks project.” They need a rhythm, a short checklist, and a way to stop preventable disputes before they become chargebacks.

Start with a weekly 30-minute review of your top codes and run this sequence:

1) Pick one bucket and fix the cause, not the dispute.
If “credit not processed” is climbing, your issue might be refund queue delays, failed refund API calls, or unclear refund timelines. If “not received” is climbing, it might be shipping cutoffs, not fraud.

2) Match evidence to the code’s defense requirements.
Different codes call for different proof. For a clear breakdown of what documents tend to matter by reason, Adyen’s guide on dispute reason codes and defense requirements is a solid reference point. Build internal templates so your team isn’t re-inventing responses.

3) Tighten the moments that create “friendly fraud.”
Friendly fraud thrives in the gaps: confusing descriptors, slow support, unclear returns, slow refunds, and subscription cancellations that feel hidden. Fixing those lowers disputes even when you never “win” a representment.

4) Add prevention where it counts, pre-dispute.
This is where tools like Chargebase fit. Chargebase is a chargeback prevention and recovery platform for e-commerce and SaaS teams, and an official partner of Ethoca and Verifi. It connects to your payment provider in minutes (no code needed) and uses global merchant data plus network programs like Verifi CDRN and RDR to spot disputes early. Instead of waiting for a chargeback to land, you get real-time alerts when an early refund or action can stop the dispute from becoming a chargeback.

Teams also like that it’s built for automation. You can apply rules to handle certain dispute types automatically (especially with RDR), which cuts manual work and reduces delays that trigger “credit not processed” claims. The pricing model is pay-per-alert, so costs track with the value of prevention rather than a big fixed platform fee.

Chargeback losses don’t come from a mystery. They come from repeatable patterns. Track your top reason-code buckets, fix the process behind them, and use chargeback reason codes as your weekly signal, not a monthly surprise. If you can prevent just the disputes that are easiest to stop (refund timing, delivery proof gaps, and subscription confusion), you’ll feel the difference in both revenue and workload.