Articles on: Frequently Asked Questions (FAQ)

What steps should I take if my update feed does not reflect accurate stock levels?

If your product feed is showing incorrect stock levels, use this troubleshooting guide to identify common causes—such as SKU mismatches, header parsing errors, or location settings—and resolve inventory discrepancies quickly.

How to Review Feed Activity and Logs

Go to syncX: Stock Sync → Feeds → Activity Log

Locate the Affected Feed: Select the product feed displaying incorrect stock quantities.
Review the Change Log: Compare source file values against the Before Qty and After Qty columns in Shopify.
Verify Product Identifiers: Check whether SKUs, barcodes, and inventory locations match between your feed file and store settings.

Always pause or disable an affected feed immediately if unexpected bulk updates occur to prevent further automated changes.

Common Causes & Troubleshooting Solutions

Identifier & SKU Mismatches

Mismatched SKUs: Ensure the SKUs in your store match the SKUs in your feed file exactly. Missing or mismatched identifiers are the most common cause of sync failures.
Non-Unique Variant Identifiers: If variants share the same SKU, only one variant will update and others may duplicate quantities. Ensure every variant has a unique identifier by combining fields (e.g., SKU + Option1 + Option2) or adding a unique column in the feed.
Duplicate SKUs Updating Unexpectedly: When multiple variants share identical SKUs, Stock Sync updates all of them with the same quantity. Include variant-level quantities in your feed if you require distinct stock levels per variant.

Column Mapping & Header Parsing Issues

Incorrect Column Mapping: Verify that your quantity field is mapped to the stock quantity column—not an inventory-tracking or boolean field. Note that field and column headers are case-sensitive.
Unreadable Headers & Row Offsets (Column Index Mapping): If the feed cannot read the file headers because the column header is on a different row or is unreadable, switch to Column Index Mapping. Mapping a field using a number (e.g., entering 5) maps it directly to column number 5 in your feed file.
File Parsing & Encoding Issues: Adjust file encoding settings or switch to column index mapping instead of header names to resolve layout parsing problems.

Inventory Location & Multi-Location Settings

Incorrect Inventory Location: Ensure the correct Inventory Location is selected in Quantity → Smart Settings. The location must also be enabled for the product or variant in Shopify Admin.

If an inventory location has not been previously activated in Shopify, a positive quantity must be synced once before that location can Subsequently be updated to 0.

Multiple Shopify Locations: Each update feed updates one Shopify inventory location at a time. Create a separate feed for each additional location and map its quantity field to the corresponding location. Ensure products are assigned to that location in Shopify.

Feed Quantity Modes & Multi-Feed Conflicts

Quantity Mode Accumulation: If a feed is set to Add/Deduct instead of Overwrite, quantities will continually accumulate rather than replacing current values. Switch to Overwrite if the feed should always set exact stock levels from the file.
Conflicting Duplicate Feed Data: Check Account → Profile for the option Use highest quantity value when same SKU detected from multiple feeds. If enabled, a duplicate SKU with a higher quantity in another feed can override lower or zero quantities in the feed you are checking. Disable this option when a feed should be the sole source for that SKU.
Real-Time Sync Timing: Real-time sync only reacts to quantity changes made after feed activation. It does not perform an initial reconciliation of existing inventory. Run a one-time update feed to align current quantities across connected stores first.

Missing Feed Items & Out of Stock Rules

Missing Products in Feed: If a supplier omits items from the feed file, syncX: Stock Sync cannot update them by default. Configure your Out of Stock Strategy and enable Remove feed-to archived discontinued products where appropriate. For products omitted from the feed, set unmatched products to 0 and apply Store Product Filters to avoid affecting unrelated products.
"0 Match" or Bulk Zero Updates: If inventory suddenly drops to zero, verify your Out of Stock Strategy settings. Some suppliers only include in-stock items in their file; your OOS rule determines whether missing items are set to zero.
Halt Threshold Pausing Updates: If more than your configured percentage of products would be set to zero, syncX: Stock Sync automatically pauses updates to protect your store. Check the Halt slider under feed settings and review the Preview Sync and Change Log before adjusting the threshold.
Accidental Bulk Zero Updates: If products not included in an update were set to 0, stop or disable the affected feed immediately. Review the feed's Change Log and Before Qty values to identify previous quantities, then create a restoration feed. Changing the product identifier to Barcode may help if barcode values are available and correctly matched.

Tag Exclusions & Filtering Rules

Product Filters or Tag Exclusions: If a product is filtered out by tags or rules in feed settings, Stock Sync will skip updating it. Review all filters to ensure items are not unintentionally excluded.

Key Rules & Technical Details

Critical priority & sequence rules:

Case Sensitivity: Column headers are strictly case-sensitive and must match feed column headers exactly.
Index Mapping Priority: Numerical column index mapping overrides column header names when headers reside on non-standard rows or are unreadable.
Location Isolation: Each update feed manages exactly one Shopify inventory location at a time.

Troubleshooting Steps

Issue: Stock quantities accumulate continuously instead of setting exact numbers. → Solution: Navigate to feed settings and change Quantity Mode from Add/Deduct to Overwrite.
Issue: Feed headers cannot be read due to header row offsets. → Solution: Map fields using column index numbers (e.g., enter 5 for column number 5) instead of header names.
Issue: Stock updates do not reflect on a specific Shopify location. → Solution: Confirm the target Inventory Location is selected in Quantity → Smart Settings and enabled in Shopify Admin.
Issue: Zero quantities are overridden by duplicate SKUs in another feed. → Solution: Go to Account → Profile and disable Use highest quantity value when same SKU detected from multiple feeds.

Good Articles to Continue

How to Map Columns using Column Indexes → Learn how to map fields using numerical column indexes when headers are unreadable.
How to Configure Out of Stock Strategy → Set up automated rules for handling missing or discontinued items in feeds.
How to Manage Multi-Location Sync in Shopify → Set up dedicated update feeds for multiple Shopify inventory locations.

Updated on: 06/10/2026

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