A supplier sends product code 00127. The stock import shows 127, and the warehouse can no longer match it to the right item. Product identifiers are labels, even when they contain only digits. Preserve their exact characters through the spreadsheet, import and database.

Find where the identifier changed

Open a copy of the original CSV in a plain-text editor and compare one affected row with the supplier’s catalogue and the imported record. If the original contains 00127 but a spreadsheet copy contains 127, inspect how the spreadsheet was opened and saved. If the file still contains all five characters, inspect the importer’s column mapping and the database field. Retain the original export so you can repeat the comparison.

Declare identifier columns as text

Microsoft’s Excel guidance on leading zeros explains how to import a text or CSV file and set a column’s type to Text. Use that approach where Excel is part of the handover and check the value again after saving. A custom display format can show leading zeros in Excel while the underlying value stays numeric. If the input has already lost digits, obtain the original again. Padding the shorter value is safe only when a verified specification gives you the exact format.

In the application, store the supplier code as text and agree whether two suppliers can use the same code for different items. Use a supplier-and-code lookup where the source owns the identifier. Decide which spaces or letter-case differences are meaningful and reject unexpected values for review. Keep quantities and amounts in separate numeric fields.

Test the round trip before updating stock

Stage a small file with 00127, 127, a long numeric-looking code and a mixed letter-and-digit code. Confirm that each expected item matches and that unknown values enter an exception list. Export the staged data again and compare the original strings, then check that no stock adjustments were made for unmatched rows. The data import reconciliation guide covers broader row and total checks.

ITZ’s custom software development service can review how your importer handles supplier identifiers. Share a sample code that changes between systems.

Review your product code import

Bring a redacted source row, the expected product code and the system that receives it. Use the form to discuss mapping, validation and a test import. Review Your Product Code Import