Import SKUs into Square without losing digits

SKUs break in the spreadsheet, not in Square. Open a supplier CSV in Excel and 0012345 becomes 12345, while a long numeric code becomes 1.2346E+10. Square then stores a code nobody can scan, or refuses the row. Square names this in its troubleshooting article. Its bulk import article recommends .xlsx over .csv for a catalog that carries SKUs. This page reads the supplier file as text from the first byte. A leading zero is still there when it reaches the SKU column. Codes already stored in scientific notation are listed, so you can see how many rows were damaged before the file reached you. Duplicate SKUs are grouped, because one code on two products confuses every count that follows.