Amazon Flat File Boolean Fields: y/n, TRUE/FALSE, and Common Pitfalls

Boolean Values in Amazon Flat Files

Amazon's category-specific Flat File templates (downloaded from Seller Central) use different boolean conventions depending on the column. Getting this wrong causes upload validation errors or silent data problems.

The three formats you will encounter:

| Format | Example | When used | |---|---|---| | y / n | y, n | Most safety and shipping boolean fields | | true / false | true, false | Some template versions, case-insensitive | | 1 / 0 | Not common | Rare; some custom flat files |

The most common mistake: Using TRUE/FALSE (Excel's default boolean display) in a column that expects y/n. Amazon rejects these with a validation error or silently ignores the field.

Common Boolean Fields in Amazon Flat Files

These columns appear in many category templates and require careful attention:

| Column name | Expected values | What it controls | |---|---|---| | batteries_required | y / n | Whether the item requires batteries | | batteries_included | y / n | Whether batteries are included in the package | | is_adult_product | y / n | Adult content designation | | is_expiration_dated_product | y / n | Whether the product has an expiry date | | item_package_quantity | integer | (Not boolean, but often confused) | | hazmat_applicable | y / n | Hazmat / dangerous goods flag | | fragile | y / n | Whether item is fragile for shipping | | is_discontinued_by_manufacturer | y / n | Discontinued product flag | | generic_keywords | text | (Not boolean — listed here to avoid confusion) |

Note: The exact column names and accepted values vary by category template. Always refer to the data definitions tab in the template you downloaded from Seller Central for your specific category.

How Spreadsheets Corrupt Boolean Values

Excel's auto-conversion

When you type y in a cell, Excel leaves it as text. But problems arise when:

1. Opening a CSV that already has y/n values: If Excel interprets the column as boolean and auto-formats it, y may be displayed correctly but saved as a platform-specific value on export.
2. Using TRUE/FALSE: If someone enters TRUE or FALSE (Excel's built-in boolean literals), Excel stores them as booleans. When exported to CSV, Excel writes TRUE or FALSE (uppercase) — which Amazon rejects for y/n columns.
3. Formulas producing TRUE/FALSE: If a formula like =IF(A2>0, TRUE, FALSE) is used to fill boolean columns, the result is TRUE/FALSE, not y/n.

Google Sheets

Same behavior: Sheets' boolean type uses TRUE/FALSE. Formulas and checkbox columns produce these values, not y/n.

Finding Invalid Boolean Values

In Excel

1. Open your Flat File CSV via Data → From Text/CSV to avoid auto-formatting.
2. For each boolean column (e.g., batteries_required): a. Click the filter dropdown. b. Look for values other than y and n. c. Flag any row with TRUE, FALSE, 1, 0, yes, no, or blank where a value is required.

Using a helper column formula

Add a column next to each boolean field to validate it:

=IF(OR(LOWER(A2)="y", LOWER(A2)="n", A2=""), "OK", "INVALID: "&A2)

Filter for rows showing INVALID to find all problem values.

Fixing Invalid Boolean Values in Bulk

Find and replace in Excel

1. Press Ctrl+H (Find & Replace).
2. In Find what, enter TRUE.
3. In Replace with, enter y (if TRUE should map to y) or n.
4. Click Options → Look in: Values to match cell values, not formulas.
5. Click Replace All.
6. Repeat for FALSE → n (or y, depending on the field's meaning).

Important: Decide the mapping for each field — TRUE might mean y for batteries_included but may not make sense for is_adult_product. Review the field meaning before mass-replacing.

Replace formula results with values

If your boolean columns are computed by formulas:

1. Select the entire column.
2. Copy (Ctrl+C).
3. Right-click → Paste Special → Values (or use the Paste Special dialog).
4. The formulas are replaced with static text.
5. Now use Find & Replace as above to convert TRUE/FALSE to y/n.

Google Sheets equivalent

1. Select the boolean column.
2. Edit → Find and replace (Ctrl+H).
3. Search for TRUE, replace with y. Apply to "This sheet."
4. Repeat for FALSE → n.
5. Check "Match case" to avoid accidentally replacing partial strings.

Preventing Future Boolean Corruption

Never use Excel boolean cells for Flat File columns

Format your boolean columns as Text (right-click → Format Cells → Text) before entering any data. This prevents Excel from interpreting y/n or TRUE/FALSE as native boolean values.

Use data validation dropdowns

In Excel, set up a dropdown for boolean columns:

1. Select the column cells (below the header).
2. Go to Data → Data Validation.
3. Under "Allow," choose List.
4. In "Source," enter: y,n
5. Click OK.

Now only y or n can be entered in those cells, preventing accidental TRUE/FALSE or freeform values.

Verify before every upload

Before uploading your Flat File to Seller Central:

1. Open the final CSV in a text editor (not Excel) and visually scan the boolean columns.
2. Confirm you see only y and n (or whatever format your template specifies).
3. No TRUE, FALSE, Yes, No, or empty cells where the field is required.

Amazon Upload Errors Related to Boolean Fields

| Error | Likely cause | |---|---| | "Invalid value for batteries_required" | TRUE or Yes instead of y | | "batteries_required is required" | Field left blank for a physical product | | Row silently ignored | FALSE used — Amazon skips the field update | | "Value not in valid range" | Using 1/0 in a y/n column |