UXFixUXFix
Language
‹ CRT-A02CHK-A01 ›
CRT-A03AI search & agents · agentLow

Cart line items include machine-readable product IDs/GTINs

Cart line items include machine-readable product IDs / GTINs.

Check my store for this rule →Cite this
Free · no card · runs all rules at once · judged on 40 stores · updated
63%of the audited stores we could judge fail this rule
15 pass0 partial25 failPublished audits · September 2026
Stores judged
40
of 40 published audits
Score weight
3.9pts
of the AI Shoppers score
Audience
AI
reported separately

What earns each verdict

Same outcomes on every UXFix rule · how verdicts work
✓ Pass15

Machine-readable IDs present.

~ Partial0

SKU present but no GTIN.

✕ Fail25

Only display names in cart data.

not assessable is recorded when the rule applied but the store could not be judged on it (bot protection, a region lock, a step we could not reach), and not applicable when the store has nothing for the rule to judge. Those stores are left out of every number on this page, never guessed. Why we do that
Why it matters

Cart line items do not include machine-readable product identifiers (SKU, GTIN, product_id). Agents see only display names.

Without a stable identifier per line, agents cannot cross-check items against a catalog, apply price rules, or reconcile the order. Display names change with translation and localization, they are not safe identifiers.

That sentence is the one a failing store sees in its own UXFix report.How rules are weighted and scored →
40 audited stores, one dot each
25 fail
PassPartialFail

Every published UXFix audit this rule could be judged on, as of 23 Sep 2026. A count of real stores, not a simulation of yours.

How we test it

Scripted walk, fresh signed-out browser · the full walk
  1. 1Fresh browserSigned out, cookies cleared, desktop and mobile viewports, the store's live theme.
  2. 2Open a productA real, in-stock product page, found the way a shopper finds one.
  3. 3Add to cartDefault variant, quantity one, then the cart page itself.
  4. 4Read it like an agentThe markup and structured data a shopping agent reads, not the layout.
  5. 5Record the verdictPass, partial or fail, saved with the screenshot it was judged on.
What the agent looks for
Cart line items include machine-readable product IDs / GTINs.
Confidence
The rulebook rates this check’s confidence High. When the agent is not sure, the rule is recorded as not assessable rather than guessed.
Not judged
0 of 40 published audits: the rule did not apply or could not be judged. Dropped, never guessed.

The numbers behind the rule

Published UXFix audits · more statistics
Published audits failing this rule
and 13 more, newest audit first.
No pictures here: this rule is judged inside the page code, which no shopper ever sees, so there is nothing to photograph.
Where this rule sits among 12 agent rules
Most-failed rank
#29
Score weight rank
#12
Fail rate
63%

Score weight: a fail costs 3.9 pts of of the AI Shoppers score; a partial costs half that. Most-failed rank is among the 79 rules with enough published audits to report a rate.

The fix

The same steps a failing store sees in its report

A pass means: Machine-readable IDs present.

Severity
Low
Score gain
+3.9pts
Page
AI search & agents

Score gain is roughly what a fail-to-pass change adds; rules that could not be judged are left out, which can move it a little. Re-run a free audit after the change ships to confirm the verdict moved.

Checklist for the pass
0 of 3

Tick each step as you ship it. The audit judges the live store, so re-run it once all of them are done.

Every store that fails this rule

The 25 audited stores that fail Cart line items include machine-readable product IDs/GTINs, with each store's published score and the day it was audited.
#StoreScoreAuditedPublished audit
1Archeryworldarcheryworld.co.uk52Open audit
2Barnesandnoblebarnesandnoble.com61Open audit
3Mujimuji.us61Open audit
4Arhausarhaus.com60Open audit
5Wpswingswpswings.com57Open audit
6Lavernelaverne.com60Open audit
7Keenfootwearkeenfootwear.com56Open audit
8Davidsbridaldavidsbridal.com58Open audit
9Bodenboden.com64Open audit
10Forever21forever21.com57Open audit
11Gymsharkgymshark.com57Open audit
12Reebokreebok.com58Open audit
13Reebokreebok.com57Open audit
14Fashionnovafashionnova.com56Open audit
15Kathmandukathmandu.com.au63Open audit
16Ladounladoun.com41Open audit
17Brewdogbrewdog.com56Open audit
18Zulilyzulily.com61Open audit
19Mejurimejuri.com65Open audit
20Timextimex.com54Open audit
21Citstorescitstores.com65Open audit
22Enviafloresparadifuntosenviafloresparadifuntos.com56Open audit
23Wpfactorywpfactory.com70Open audit
24Iliabeautyiliabeauty.com62Open audit
25Tentreetentree.com58Open audit

What our auditors say about this rule

Without a product id on the cart line, an agent knows what it costs and not what it is.
Abdulhameid Grandoka, Co-founder, UXFix

Written by the person who audits this rule, and reviewed every quarter.

What this rule rests on

The published research and standards this rule is drawn from. Open them and check the reasoning for yourself.

Keep going

All rules →
Agent rulePDP-A01
Complete Product schema.org: price, availability, GTIN/SKU, rating, shipping detailsAI search & agents · High ›
Agent rulePDP-A03
llms.txt present at root; product URLs not bot-blockedAI search & agents · Medium ›
Agent rulePDP-A04
Canonical URLs stable; variant URLs machine-readable and permanentAI search & agents · Medium ›
Agent ruleCRT-A01
Cart state reachable via stable URL or API endpointAI search & agents · Medium ›
Agent ruleCRT-A02
No session trap that breaks agent-driven cart hydrationAI search & agents · Medium ›
Agent ruleCHK-A01
Agentic checkout readiness signals (ACP/UCP endpoints declared)AI search & agents · High ›
Agent ruleCHK-A02
No CAPTCHA-only gate without accessible agent pathAI search & agents · Medium ›
Agent ruleCHK-A04
Delegated-payment compatibility signals present (tokenization endpoints)AI search & agents · Medium ›
Cite this

«25 of 40 online stores audited by UXFix fail the rule "Cart line items include machine-readable product IDs/GTINs" (CRT-A03) as of September 2026. UXFix, uxfix.ai/audits/rules/product-ids-in-cart-lines»

Rule record · JSON
Dataset →
{
  "id": "CRT-A03",
  "name": "Cart line items include machine-readable product IDs/GTINs",
  "area": "agent",
  "severity": "low",
  "weight": 3.85,
  "published_audits": {
    "judged": 40,
    "pass": 15,
    "partial": 0,
    "fail": 25
  },
  "updated": "2026-09-23"
}
Check your store

Does your store pass CRT-A03?

One address, every rule, the verdicts with the screens they were judged on.

Run the free audit →
Free, no card. See what the full report adds on pricing.
‹ Previous rule · CRT-A02No session trap that breaks agent-driven cart hydrationNext rule · CHK-A01 ›Agentic checkout readiness signals (ACP/UCP endpoints declared)
Free · no card · about 3 minutes

Audit my store, free.

115 rules on your product page, cart and checkout. Nothing to install.