What is Amazon Seller Central's flat file row limit?

Amazon recommends keeping flat files under 10,000 rows and 2MB per submission for reliable processing. Larger files may time out or return processing errors.

Will the header template row be included in every chunk?

Yes. Every output file includes the original header row from your source file. Amazon's flat file importer requires this row to map columns correctly.

Can I use this for FBA shipment or inventory adjustment files?

Yes. Any Amazon-format CSV — flat files, inventory loader files, price and quantity feeds — can be split by row count using this tool.

What happens if I accidentally omit the header row from a Seller Central upload?

Amazon will reject the file with a format error or mismap all columns, resulting in processing failures. Using this tool ensures every chunk has the correct header automatically.

Split Amazon Flat Files and Inventory CSVs Into Seller Central–Ready Chunks

Amazon Seller Central's bulk upload tools impose file size and row count limits that catch sellers off guard when managing large catalogs. A flat file with 50,000 ASINs cannot be uploaded in one pass — it must be split into smaller files that fall within Seller Central's accepted thresholds.

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Amazon recommends flat files stay under 2MB and typically under 10,000 rows per submission for stable processing. Sellers managing large private-label catalogs, wholesale inventories, or FBA replenishment feeds regularly hit these limits. Manually splitting in Excel risks dropping the header row — which causes the entire upload to fail with a cryptic format error.

Deliteful splits your flat file or inventory CSV into fixed-row chunks with the header preserved in every output file. Since Amazon's flat file importer requires the header template row to be present, this is non-negotiable. Set your limit to 9,500 rows for a safe margin, download the numbered chunks, and upload them sequentially through Seller Central's Add Products via Upload workflow.

How it works

1
Export your Amazon flat file or inventory report
Download the flat file template with your product or inventory data from Seller Central or your inventory management system.
2
Set row limit to 9,500 for a safe Seller Central margin
Amazon recommends files under 10,000 rows — use 9,500 to stay safely within limits and account for any processing overhead.
3
Upload each chunk sequentially via Add Products via Upload
Each output file includes the required header row; upload them one at a time and monitor processing status in Seller Central.

Frequently asked questions

What is Amazon Seller Central's flat file row limit?: Amazon recommends keeping flat files under 10,000 rows and 2MB per submission for reliable processing. Larger files may time out or return processing errors.
Will the header template row be included in every chunk?: Yes. Every output file includes the original header row from your source file. Amazon's flat file importer requires this row to map columns correctly.
Can I use this for FBA shipment or inventory adjustment files?: Yes. Any Amazon-format CSV — flat files, inventory loader files, price and quantity feeds — can be split by row count using this tool.
What happens if I accidentally omit the header row from a Seller Central upload?: Amazon will reject the file with a format error or mismap all columns, resulting in processing failures. Using this tool ensures every chunk has the correct header automatically.

Sign up free with Google and split your Amazon flat files into Seller Central–ready chunks without risking a missing header row.