How to Bulk Add identifier_exists to Shopify Products (For Unbranded and Custom Items)

If your products genuinely have no GTIN, MPN, or brand — handmade goods, custom-order products, private-label below the GTIN threshold — you have to tell Google explicitly with identifier_exists=false. Skipping this step doesn't make Google ignore the missing identifier; it surfaces "missing GTIN" errors against your account and, in 2026, can escalate to suspension under the misrepresentation policy. The fix is a one-time metafield definition plus a bulk pass via CSV import. Most Shopify stores can clear hundreds of products in 30 minutes once the setup is right.

This post is the bulk-edit playbook. It assumes you've already determined identifier_exists=false is the right answer for these products — if not, why "missing GTIN" shows on your Shopify Google channel walks the decision tree.

When identifier_exists=false is the right answer

Four product categories where this is correct:

• Truly unbranded products that you sell under no brand at all (rare but it happens — generic accessories, plain commodity items).
• Custom or made-to-order products where each unit is unique (custom embroidery, made-to-measure, personalized goods).
• Handmade products without manufacturer-assigned identifiers (artisan jewelry, small-batch crafts).
• Private-label products below the GTIN registration threshold — your own brand, your own SKUs, no GS1 registration.

Where it's not right:

• Branded resale (Nike, Apple, anything you didn't make). Use GTIN. See the missing GTIN post.
• Dropshipped name brands. Same — use GTIN, even if the supplier won't share it (set identifier_exists=false only as a last resort here).
• Products under your own brand where you DO have manufacturer codes. Use the MPN+brand path. See how to add MPN and brand metafields to Shopify products.

The risk of setting it wrong

Two failure modes, very different in severity:

• False positive (using identifier_exists=false when products DO have GTINs). Mild ranking penalty. Google deprioritizes you on contested queries because you're missing a verification signal it could have used. Performance hit, no suspension risk.
• False negative (not using it when needed). Severe. Products show "missing identifier" errors. Repeated occurrences trigger account-level "missing identifier" warnings, which escalate to misrepresentation suspensions. See why GMC suspends accounts in 2026 for how this lands in the suspension reason map.

Err on the side of setting identifier_exists=false for genuinely unidentified products. The penalty for false-positive is much smaller than the penalty for false-negative.

Step-by-step bulk method 1 — CSV import

Works for 100-2,000 products. Above that, the CSV gets unwieldy and method 2 (Matrixify) is better.

Step 1: Create the metafield definition. Settings → Custom data → Products → Add definition. Namespace and key: custom.identifier_exists. Type: Single line text. Save.

Step 2: Export products CSV. Products list → Export → All products. Wait for the email with the download link.

Step 3: Add the custom.identifier_exists column. Open the CSV in your spreadsheet of choice. Shopify's native export does not include all metafield columns by default — you may need to add the column manually with header Custom: identifier_exists [single_line_text_field] (the exact format depends on Shopify's current CSV schema; verify by exporting a single product after Step 1 and inspecting the column header).

Step 4: Set value to false for affected rows. Filter or sort the CSV to identify the products that need identifier_exists=false. For each, set the new column to false. Leave it blank for products that should retain identifiers.

Step 5: Re-import. Products → Import → Add file. Shopify will overwrite metafield values for matching products. Review the import preview before confirming.

Caveat: Shopify's native CSV import is fragile around metafields. If you have errors, fall back to method 2.

Step-by-step bulk method 2 — Matrixify

For large catalogs (2,000+ products) and complex metafield setups, Matrixify is the standard tool. Quick walkthrough:

1. Install Matrixify from the Shopify App Store.
2. Export → Products → include metafields. Choose Excel format for easier editing.
3. Edit the Metafield: custom.identifier_exists [single_line_text_field] column. Set to false on affected rows.
4. Import the file back. Matrixify shows a preview of every change before commit. Review carefully — bulk metafield writes are hard to reverse.

Matrixify scales to 50,000+ products in a single import and gives detailed error reporting if any rows fail. The monthly fee pays for itself the first time a native CSV import silently corrupts your data.

Step-by-step bulk method 3 — automation app

ShieldKit's Shield Max tier includes a bulk identifier auto-filler. The tool scans your catalog, detects products without GTINs/MPNs/brand, and groups them into "should set identifier_exists=false" vs "should populate brand+MPN" buckets based on category and vendor heuristics. For the first bucket, it writes the metafield in bulk; for the second, it surfaces the products for manual review.

Caveat: write access for this tool is gated on the write_products Shopify scope, which is currently in App Store re-review. The detection and preview UI work today — it's a useful diagnostic even if you do the actual writes via Matrixify. Run a free compliance scan to see what the auto-filler would target.

What to do for products that have brand but no MPN/GTIN

Different path. Don't set identifier_exists=false — instead populate custom.brand and explicitly leave MPN and GTIN unset. Google's spec accepts brand-only as long as you also signal that the brand is the only available identifier (typically by setting identifier_exists to true and providing brand only).

In practice, brand-only is a weak identifier and Google will flag it for catalog match issues. If your products genuinely have brand and nothing else, the cleanest fix is to set identifier_exists=false and accept the small ranking penalty — even though brand exists, the product may not be matchable in Google's catalog without MPN or GTIN.

For mixed cases (some products have brand+MPN, others don't), use a combination: brand+MPN where you can, identifier_exists=false otherwise. Don't try to apply one rule to the entire catalog.

Verification after bulk update

• Wait 24-72 hours for the Google channel to re-sync.
• GMC Diagnostics → Item issues. "Missing identifier" entries should clear for the products you updated.
• Spot-check 10 products in GMC → Products → All products. The "Identifier exists" column should show "No" for affected products.

If errors persist after 72 hours, the most common cause is namespace mismatch — your channel app may be looking for mc_google_offer.identifier_exists instead of custom.identifier_exists. Repopulate one product under the alternate namespace and verify which sticks.

For the broader pattern of product feed errors that don't surface cleanly in diagnostics, see Shopify products not showing in Google Shopping and the 12-point GMC compliance checklist.

Common mistakes

Five patterns we see when auditing stores:

• Setting identifier_exists=false on branded resale. This is a major mistake. Branded products have GTINs by definition; setting identifier_exists=false is misrepresentation and triggers suspension. Use the GTIN path for branded resale.
• Setting identifier_exists=true while leaving GTIN/MPN/brand all empty. Contradictory. The default is "true," so omitting the metafield is the same as setting true. If you set true explicitly, populate at least one of GTIN, MPN, or brand+MPN.
• Forgetting variant-level identifier requirements. If your product has variants and they have different identifiers (sizes with different barcodes), apply the rule per variant, not per product.
• Bulk-writing without testing on one product first. A namespace error on a 10,000-product import is a multi-hour mess to clean up. Always test on one product, wait 24-72 hours, verify, then bulk.
• Not running a compliance scan after. A quick scan confirms the bulk write actually propagated. Don't trust the import success message — verify on the GMC side.

FAQ

Where do I set identifier_exists on Shopify?

Create a product metafield under namespace custom, key identifier_exists, type single-line text. Then set value to false for products that need it. Some Google channel app versions use the mc_google_offer namespace instead — check yours by populating one product and inspecting the GMC feed.

Can I bulk set identifier_exists via Shopify's native CSV?

Yes, but it's fragile. Shopify's CSV import sometimes silently drops metafield columns or rejects the import on cosmetic schema mismatches. Matrixify is more reliable for catalogs over a few hundred products.

What's the difference between identifier_exists=false and just leaving GTIN empty?

Leaving GTIN empty triggers "missing GTIN" errors. Setting identifier_exists=false tells Google explicitly that no identifier exists for this product — it's a different signal that clears the error.

Will identifier_exists=false hurt my Google Shopping rankings?

Slightly. Products without verified identifiers rank below otherwise-equivalent products with GTINs on contested queries. The penalty is small — 5-15% impression reduction in our experience — and far better than a suspension.

How long until GMC reflects the change?

24-72 hours for the Shopify Google channel to re-sync, plus another 24 hours for GMC Diagnostics to refresh. Total 1-3 business days.

Can I undo a bulk identifier_exists write?

Yes — re-export, clear or change the metafield values, re-import. There's no version history on metafields, so make a backup of the original CSV before any bulk write.

For Google's official identifier requirements, see Google's product data specification on identifiers. For Shopify's metafield import documentation, see Shopify's product CSV import help.