Amazon Bulk Upload in Seller Central: CSV & Spreadsheet Workflow

To bulk upload listings to Amazon Seller Central, download Amazon's template for your product type (under Catalog, then Add Products via Upload), fill one row per SKU using the exact values in the template's Valid Values tab, upload the file from the same page, and then download the processing report to fix any rows that failed. A plain CSV with your own column names will not work: Amazon only reads its own templates. This guide covers the overall bulk upload workflow, which tool to use when, and the habits that keep big uploads safe. For a column-by-column deep dive on templates, variations and error codes, see our flat file guide.

What Are Amazon Flat Files?

Amazon flat files (Seller Central also calls them inventory files, category templates or listing spreadsheets, and the labels change over time) are spreadsheet templates, usually Excel workbooks, with tab-delimited text accepted for many uploads, that allow sellers to create, update, or delete product listings in bulk through Seller Central. Instead of manually editing one listing at a time through the web interface, flat files let you modify hundreds or thousands of listings simultaneously by uploading a single file.

Think of a flat file as a structured spreadsheet where each row represents one product listing and each column represents a specific attribute — title, bullet points, price, images, keywords, and dozens of category-specific fields. You fill in the data, upload the file, and Amazon processes it to create or update your listings.

For sellers managing more than 10-15 ASINs, flat files are not just a convenience — they are a necessity. Manual listing management at scale is error-prone, time-consuming, and makes it nearly impossible to maintain consistency across your catalog.

When to Use CSV/Flat File Upload vs. Manual Entry

Not every situation calls for a flat file. Here is when each approach makes sense.

Use Flat File Upload When:

• Launching multiple products at once. If you are adding 5+ listings, flat files save significant time.
• Updating attributes across many listings. Need to change your brand name, update pricing, or revise bullet points for your entire catalog? Flat files let you do it in one upload.
• Migrating from another marketplace. Moving your catalog from Walmart, Shopify, or another platform to Amazon is far easier with flat files.
• Seasonal updates. Holiday-specific titles, descriptions, or pricing changes across dozens of ASINs are best handled in bulk.
• Backend keyword updates. When you have new keyword research for multiple listings, flat files let you update all search terms simultaneously.
• Creating variation families. Parent-child relationships (size, color, pattern variations) are significantly easier to set up via flat files than through the manual interface.

Use Manual Entry When:

• Creating 1-3 listings. The overhead of downloading and learning the flat file template is not worth it for a few listings.
• Updating a single field on one ASIN. Quick edits are faster through the Seller Central listing editor.
• You are a new seller. Learning the Seller Central interface manually first gives you a better understanding of how Amazon structures listing data before you jump to flat files.

The Bulk Upload Tools in Seller Central

"Bulk upload" covers several different tools. Picking the right one is the first step of the workflow.

Menu names move around, but all of these live under Catalog (Add Products via Upload) or Inventory (inventory reports) in Seller Central.

How to Download Your Category-Specific Template

Amazon provides different flat file templates for different product categories. A template for Electronics will have different fields than one for Grocery or Clothing. Here is how to get the right template.

Step-by-Step: Downloading the Template

• Log in to Seller Central for your marketplace (for example sellercentral.amazon.com or sellercentral.amazon.in)
• Navigate to Catalog > Add Products via Upload
• Open the option to download or generate a template (the tab label changes between versions)
• Search for your product type (e.g., "wireless earbuds") and select the most specific match; you can usually add several product types to one template
• Select the marketplace, and if Amazon offers a choice of template modes, pick the one that includes all attributes so you do not miss category-required fields
• Click Generate and download the Excel file

Download a fresh template for every new batch. Amazon updates required attributes and valid values, and an old file can fail on columns that have changed.

Understanding the Template Structure

Your downloaded template will contain multiple tabs:

• Instructions: Overview of how to use the file (read this first)
• Data Definitions: Column-by-column explanation of every field, including character limits, valid values, and whether the field is required or optional
• Template: The actual data entry sheet where you fill in your listings
• Example: Pre-filled sample rows showing correctly formatted data
• Valid Values: Dropdown lists for fields that only accept specific values (condition type, variation theme, etc.)

Some versions also include extra sheets, such as image guidance or a browse tree guide. Newer templates may show friendlier column labels above longer attribute names, so the exact headers in your file can differ from the classic names used below.

The most common mistake sellers make is ignoring the Data Definitions tab. Spend 15 minutes reading through the field requirements for your category before entering any data.

Required Fields: What Every Flat File Must Include

While Amazon's flat file templates contain hundreds of columns, only a subset are required for a successful upload. Here are the essential fields you must populate.

Universal Required Fields

item_sku — Your unique internal identifier for the product. This does not appear to customers but is how Amazon links your inventory, orders, and reports to this specific listing. Best practice: use a consistent naming convention (BRAND-CATEGORY-VARIANT-001).

feed_product_type — The product type, chosen from the Valid Values tab. Newer templates often prefill it based on the product type you selected.

external_product_id — The product's UPC, EAN, GTIN or ISBN. Brand owners with an approved GTIN exemption can list without one. GTINs should be licensed from GS1 and registered to the brand on the listing.

external_product_id_type — Specifies which type of product ID you provided (UPC, EAN, GTIN, ISBN).

item_name — Your product title. Since July 27, 2026, Amazon is reported to cap titles at 75 characters, spaces included, for all categories except media; older templates may still show 200 characters in Data Definitions. Details that no longer fit can go in the new Item Highlights field where it is available.

brand_name — Your brand name. Must match your Brand Registry entry, and the GS1 record for your GTINs, exactly.

manufacturer — The manufacturer name. Can be the same as brand_name for private label sellers.

item_type — The product type keyword that Amazon uses to classify your listing. Selected during template generation.

quantity — Available inventory count (for MFN/FBM sellers). FBA sellers can often leave this blank as Amazon manages FBA inventory separately.

standard_price — Your selling price in the marketplace currency.

Fulfillment channel — Templates handle this differently; follow the Data Definitions tab for whether the offer is merchant fulfilled (FBM) or fulfilled by Amazon (FBA).

Content Fields (Critical for Optimization)

bullet_point1 through bullet_point5 — Your bullet points. Character guidance varies by category and is shown in Data Definitions; shorter, scannable bullets read better on mobile. These are indexed for search and are your primary text selling tool.

product_description — Your product description, commonly up to 2,000 characters. Brands with A+ Content usually see the A+ modules displayed in place of the plain description on the detail page.

generic_keywords — Your backend search terms. On Amazon.com and most marketplaces this must stay under 250 bytes; Amazon.in has historically used a lower limit, around 200 bytes. Going over can stop the field being indexed, so keep a margin (see our backend search terms guide).

main_image_url — The URL for your main product image. Must be a publicly accessible URL pointing to an accepted image file (JPEG is the safest choice) on a pure white background.

other_image_url1 onward — URLs for your secondary gallery images.

Category-Specific Required Fields

Depending on your category, additional fields may be required. Common examples:

• Clothing: size_name, color_name, department_name, material_type
• Electronics: wattage, voltage, battery_type, wireless_communication_technology
• Grocery: item_form, allergen_information, serving_size, unit_count
• Beauty: item_form, skin_type, scent, target_gender

Amazon will reject your upload if category-specific required fields are missing. Always check the Data Definitions tab for fields marked as "Required."

Common Bulk Upload Errors and How to Fix Them

Flat file uploads often fail on the first attempt. The processing report gives an error code, the SKU and usually the column for every failed row. These are the codes sellers see most often (Amazon's exact wording changes, so treat the report as the final word):

Our flat file guide walks through each of these, plus parent-child variation errors, in more detail.

Encoding and Formatting Errors

Garbled characters or encoding issues. If you save a template as text, use UTF-8 encoding (in Excel, choose the UTF-8 or Unicode text option). Special characters such as accents and symbols can corrupt in other encodings. Uploading the original Excel workbook avoids most of these problems.

Line breaks within fields. Amazon flat files use tab-delimited formatting where each line represents one product. If your bullet points or descriptions contain line breaks, they will break the file structure. Remove all line breaks from within field values.

Extra commas or tabs. Even one misplaced tab character shifts every subsequent column, causing cascade failures across multiple fields. Use the template's built-in structure rather than copying from external spreadsheets.

How to Upload Your Completed Flat File

Once your file is complete and error-free:

• Go to Catalog > Add Products via Upload in Seller Central
• Open the upload option (the tab label varies between versions)
• Select the file type that matches your template
• Choose your file and click Upload
• Amazon begins processing immediately

Processing Timeline

Amazon does not publish fixed processing times. Small files often finish within minutes, while large files or busy periods can take hours.

After processing, check the upload status section on the same page. Amazon will provide a processing report showing:

• Successful records: Listings that were created or updated
• Warning records: Listings that processed but with non-critical issues
• Error records: Listings that failed, with specific error codes

Download the processing report and address all errors before re-uploading. Fix failed rows in your original file, remove the rows that succeeded, and upload only the corrections. Read warnings too: a row can succeed while an attribute was ignored.

Partial Updates: Editing Existing Listings via Flat File

You do not need to re-upload your entire catalog every time you want to make changes. Amazon supports partial updates where you include only the fields you want to change.

Partial Update Requirements

The easiest starting point is the Category Listings Report (under Inventory reports, where available in your account), which downloads your existing listings as a spreadsheet you can edit. In each row of a partial update you need:

• item_sku — To identify which listing to update
• update_delete — Set to "PartialUpdate"
• The field(s) you want to change — Leave every other column blank (some templates also expect the product type)

This is incredibly powerful for bulk operations like:

• Updating backend keywords across 200 listings after new keyword research
• Adjusting prices for a seasonal promotion
• Revising bullet points with improved copy
• Adding new image URLs

Important: The "update_delete" Column

This column controls what Amazon does with your upload:

• Update — Creates new listings or fully overwrites existing ones (blank fields will erase existing data)
• PartialUpdate — Only modifies the fields you include (blank fields are ignored, preserving existing data)
• Delete — Removes your offer for that SKU

Always use "PartialUpdate" unless you specifically intend to overwrite all fields. Using "Update" with blank fields will erase existing content — a common and painful mistake.

Mapping External Data to Seller Central Fields

If you are using listing generation tools, the output needs to map correctly to Amazon's flat file structure. Here is how standard listing components correspond to flat file fields.

When using zonfy.app to generate your listing content, you get a title, bullets, description and backend search terms that you can copy into the corresponding template columns, or export as a CSV of the copy and paste it across. Always run a final check against your category's current limits before uploading.

Flat File Best Practices

Always back up before uploading. Download your current listings as a flat file before making bulk changes. If something goes wrong, you have a restore point.

Test with a small batch first. Before uploading changes to 500 listings, test with 5-10 SKUs first. Verify the results in Seller Central, then proceed with the full batch.

Use consistent formatting. Establish standards for how you format titles, bullet points, and descriptions across your catalog. Flat files make inconsistency painfully obvious.

Version your files. Name your flat files with dates and descriptions: "Electronics_BulletUpdate_2026-04-05.xlsx." You will thank yourself when you need to troubleshoot an issue from three months ago.

Be careful with Google Sheets for the final file. Converting the template can strip its dropdowns, hidden rows and formatting. Upload the Excel workbook Amazon gave you, saved from Excel or LibreOffice Calc, or save as UTF-8 tab-delimited text if your file type accepts it.

Schedule regular bulk updates. Set a monthly cadence for reviewing and updating your flat files. Keyword research evolves, pricing strategies change, and your content should keep pace.