Flat file
A flat file is a plain text file holding one table, one record per line, such as a CSV; Amazon also uses the name for its listing templates.
- Amazon flat file
What it means
A flat file holds a single table and nothing else: one record per line, the same columns on every line, and the values split by a character such as a comma or a tab, or set at fixed widths. Microsoft’s import tool copies data “from a flat file (for example, .csv or .txt) to a new table”, with separators including “commas, tabs, semicolons, and pipes”.1
Flat means the file stands alone, with nothing linked to it. Collins defines a flat-file database system as one in which each database is “a single file not linked to any other file”.2 A CSV is a flat file, and so is a tab-delimited text file.1
On Amazon, flat file means the spreadsheet templates used to list products in bulk: its help tells sellers to check “the Data definition and Valid values tabs in category-specific flat files before you upload”.3 Its current name for them is bulk listing templates. Products go in one row per SKU, and the finished file can be uploaded as an Excel workbook or as tab-delimited text.45
Think of it like this
It is like the visitors’ book in a holiday cottage: one line per visit, the same columns on every line (date, name, where from), and everything about a visit on its own line. Nothing points to another page, which is what makes it flat.
For example
A supplier’s price list puts the brand in a merged cell above each block of products, and the sizes of a shirt side by side in one row. As a flat file with a pipe between values, each size gets a line of its own and the brand is repeated on every line: Lowmere|RV-SHIRT-S|Linen shirt|S, then Lowmere|RV-SHIRT-M|Linen shirt|M.
Why it matters
An import reads the file literally, so it has to be truly flat: one product per row and one value per cell, with no merged cells and no compound value such as S/M/L in a single cell. Amazon’s processing report then points back to rows by number, and because the template’s first two rows are headers, “Record 1 in the processing report corresponds to Row 3 in your inventory file”.4
Not to be confused with
Sources
- Microsoft Learn. Import Flat File to SQL Wizard.
- Collins English Dictionary. Definition of ‘flat-file’ (American English).
- Amazon Seller Central UK. Attributes guide.
- Amazon Seller Central UK. Bulk listing templates.
- Amazon Seller Central UK. Build your inventory file.
- Amazon Selling Partner API, Developer Hub. Deprecation of Feeds API support for XML and Flat File Listings Feeds.
- Amazon Selling Partner API, Developer Hub. Update: Removal date of Feeds API support for XML and flat file Listings Feeds changed to July 31, 2025.