Your Product Code Started With a Zero. Where Did It Go?

A product code in your source system is 001. After opening an export in a spreadsheet and saving it again, you see 1.

If the spreadsheet treated the code as a number, it may have removed the leading zeros. That matters when the code is an identifier: 001 and 1 can represent different records.

Check the source before changing anything

Open a copy of the original CSV in a plain-text editor and find a known code. Compare it with the version you saved from the spreadsheet. If the original says 001 and the new file says 1, the change happened somewhere between those versions.

A CSV can contain 001 as text, but a spreadsheet may interpret that value as a number when opening it. When importing a file, set the product-code column to Text in the import settings. Then inspect a few known IDs before saving a new copy. Quoting a CSV value alone doesn't guarantee that a spreadsheet will preserve its zeros.

If the zeros are already missing, don't add them back by guessing. Check the source system or an unchanged export to learn the real IDs. Different codes may have different lengths.

Compare two versions using the right key

CSV Reconcile Desk compares two CSV or TSV files by an ID column. It treats 001 and 1 as different strings, so they won't silently match. Select the fields you want to compare and review added, missing and changed records; duplicate and blank IDs are listed separately.

The app runs locally in your browser and can export a CSV or JSON report. It does not restore lost zeros or decide which code is correct; you need the original source for that. XLSX is not supported.

RUB 990 as a one-time purchase: Get CSV Reconcile Desk.

I'm Daniil Kornilov, author of Kornilov Tools. Follow this blog for simple ways to check files and avoid confusing data errors.

Have you ever seen an identifier change after a file was opened or exported?