Common Transparency Code Errors and How to Fix Them
By Todd Welch, founder of T-Code Manager. Published October 13, 2026.
Most Transparency problems come from a short list of mistakes: the wrong code, the same code twice, a code that won't scan or no code at all. Each one has a predictable cause and a fix you can put in place before the next shipment.
Here are the common ones, what causes them and how to stop them. Amazon's exact error messages change over time, so this guide goes by what's happening rather than by message text.
1. Amazon won't accept a code at shipment confirmation
What it looks like: you enter codes for an FBM order in Seller Central or your shipping software, and one or more are rejected.
Common causes:
- A typo. Codes are long, and one wrong character makes a code invalid.
- Extra characters copied along with the code, like a space, a line break or a comma.
- A prefix the field doesn't expect, or a missing one. Some codes start with "AZ:", and tools differ in whether they want it.
- A code from a different product. Codes are issued for specific products.
- A code that was already used.
Fix: never retype codes. Copy and paste them. If one is rejected, check it for stray characters and check the format the tool expects. Then confirm the code came from that product's codes and hasn't been used before.
2. The number of codes doesn't match the units
What it looks like: an order has three units of an enrolled product and you only have one or two codes entered.
Cause: treating codes as one per order or one per line item instead of one per unit. Orders with several enrolled SKUs or large quantities make this easy to get wrong.
Fix: one code per unit, always. An order for three units needs three codes. Pull codes by quantity, not by line.
3. Shipping confirmation file uploads fail for some orders
What it looks like: a bulk upload goes through, but some orders don't take their codes.
Cause: Amazon doesn't publish limits for confirmation file uploads. Orders with several enrolled SKUs or a large quantity of one enrolled SKU are the ones to watch, because they carry the most codes per order.
Fix: test the file on a small batch first. After every upload, confirm Amazon accepted the codes for every order. Enter any problem orders by hand in Seller Central.
4. The same code ended up on two units
What it looks like: you find a code twice in your records, or the brand's performance report shows a problem you can't explain.
Common causes:
- Two people printing from the same CSV file
- Marking codes used after printing instead of before
- The same file loaded twice
- Reprinting a job without checking which codes were in it
Fix: mark each code used at the moment it's printed or handed out, from one shared inventory. Keep original files locked away so nobody prints from them directly. If a duplicate already shipped, find out where both went and talk to Transparency support.
5. Codes won't scan
What it looks like: your scanner, the fulfillment center or a customer can't read the code.
Common causes:
- Print scaling set to "Fit to page," which shrinks the code
- Darkness set too low, or a worn print head
- Faded direct thermal labels that sat in heat or sunlight
- A label wrapped around an edge, wrinkled or on a curved surface
- Tape or another label covering part of the code
Fix: print at 100% or "Actual size," test-scan the first label of every job and apply labels flat on one surface. The full setup is in how to print Transparency labels.
6. A code from the wrong product
What it looks like: a unit carries a valid code, but it was issued for a different product.
Common causes:
- Scanning the wrong barcode on a multipack or a similar-looking product
- Variations, like sizes or colors, with nearly identical packaging
- Codes loaded under the wrong product when the file came in
Fix: check the product on screen before every print. Name code files by product the moment they arrive, and load each file only against the product it was issued for.
7. FBA units blocked at receiving
What it looks like: the brand's performance report shows units blocked from shipment for missing or invalid codes.
Cause: any of the errors above, on units sent to a fulfillment center, where Amazon scans codes as units arrive.
Fix: find which shipment and which units, find the cause and fix it before the next shipment goes out. Ask Transparency support how to handle the units already there. See what happens when units ship without codes.
8. A listing or offer is rejected
What it looks like: you try to list an enrolled product and Amazon won't take it.
Cause: Amazon says fully protected products can't be listed without matching valid codes. This most often hits resellers who don't have codes from the brand yet.
Fix: get codes from the brand first. Ask whether units come pre-labeled, whether the brand will send code files or whether it will authorize API access.
9. Running out mid-shift
What it looks like: a packer opens the file for a product and there are no codes left.
Cause: nobody was watching the count, or the reorder point was set for the whole catalog instead of per product.
Fix: set a reorder point for each product, get an alert before you hit it and reorder with enough lead time. See ordering codes in bulk.
10. Protection isn't switching on
What it looks like: you enrolled weeks ago, but protection still isn't active.
Cause: protection doesn't start until the product passes the operational performance review. Amazon's Canadian and Australian pages say the bar is 98% accuracy. Missing, duplicate and wrong codes all pull your accuracy down.
Fix: go through every error on this list, fix the ones that apply and ask your Transparency contact where the review stands.
11. Nobody can say where a code went
What it looks like: Amazon, a brand or a customer asks about a specific code and you can't answer.
Cause: codes were used without being logged against an order or shipment.
Fix: log every code with the product, the order or shipment and the date, and reconcile monthly. Here's how to reconcile Transparency codes.
How T-Code Manager prevents most of these
T-Code Manager is built around this list.
- No retyping. For FBM orders, copy one code at a time, or copy them all one per line or comma separated. There's an option to strip the "AZ:" prefix for pasting into ShipStation.
- One code per unit. Enter the quantity and you get that many unused codes, logged with the order ID.
- No duplicates. Codes are marked used as soon as the label file is created or the codes are dispensed, so two stations can't get the same code.
- No lost codes on a failed job. If the label file fails to generate, no codes are used up.
- Codes left per product. The dashboard shows every product's count, and low-stock emails warn you before you run out.
- A full history. Every print job and dispense is logged with who ran it, when, the product and the order or shipment.
New to the FBM side? Start with the FBM labeling guide. Ready to try it? Start a free 14-day trial, no credit card required, or see pricing.