# Check your product data before a shop–warehouse sync

> Drop the export from your stock program. We show which items will link to your online shop on their own, which need a mapping table and which have errors, in your browser and without uploading the file.

## What we check

We read the export in your browser: CSV, XLSX or XML, in UTF-8 or windows-1251. We recognise the columns by their headers and go through every row: empty and repeated codes, barcodes with a wrong check digit or shortened by Excel, lost leading zeros, prices stored as text, at zero or below it, negative and fractional stock, VAT rates other than 20, 9 and 0 %, variants hidden in names, and the groups. We never run formulas or macros.

## What people ask

### How do I check the barcodes in a stock export?

Drop the export into the check above. For every barcode we work out the EAN-8, EAN-13, UPC-A and GTIN-14 check digit, look for codes Excel has stored as 3.8E+12, 12-digit barcodes that have lost their leading zero, and one barcode on two items. You see the affected rows on screen and can download them as a list.

### Why does Excel break barcodes?

Excel reads a long barcode as a number. It shows it as 3.8E+12 and, when you save as CSV, writes it that way too, so the other digits are lost. As a number it also drops the leading zero. Export straight from your program, or import the column as text.

### Which file should I export from my stock program?

The item list with code, barcode, name, price, stock, VAT, unit and group, as CSV or XLSX. Most programs have that export under items or reports. If you cannot find it, tell us which program you use; we work with any of them and will tell you what export or API it has.

### Do you upload the file?

No. The file is read in your browser and is not sent to us or to anyone else. If you send an enquiry, it holds only the counts and the kinds of error, never the file's content.

### What happens if the codes do not match?

You make a mapping table: which warehouse code goes with which shop product. Codes that differ only by spaces, capital letters or leading zeros link after a clean-up. The rest are linked by hand once, and the sync keeps them from then on.

Page: https://tnb-tech.com/en/product-data-check/