Supplier data for a product import: what to check

A supplier CSV can look tidy and still cause trouble when you import it. Product codes may lose leading zeros, prices may use different currencies, or a column may contain values your catalog cannot accept.

Do a quick check before uploading the file. The CSV Editor opens large CSVs in your browser and lets you find, edit, sort, and remove duplicate rows. Use it to spot data problems before they spread through your product catalog.

Review the supplier CSV before importing

1. Open the supplier file in the CSV Editor. Keep the original file unchanged and work from a separate copy if you plan to make corrections.
2. Read the column headings first. Identify which columns hold the supplier's product code, your SKU, product name, description, price, quantity, category, and image link. A heading such as Item No. may mean a supplier ID, not the SKU your store uses.
3. Scan representative rows from the top, middle, and end. Look for blank required fields, unexpected values, and formatting that changes between rows. Use search to find a value you expect to be consistent, and sort a column to bring similar values together.
4. Check identifiers and duplicates. Confirm that codes keep their full spelling, including any leading zeros. Sort the SKU or product-code column and inspect repeated values before removing anything. Different sizes or colors may need separate rows, even when their product names are nearly identical.
5. Compare the supplier's fields with the importer's field mapping. Check a small sample of rows in the import preview before bringing in the full file, and make sure each source column is assigned to the intended destination.

If codes such as 00147 become 147, the import may treat them as different products or fail to match existing records. See why leading zeros disappear from CSV data before changing an identifier column.

What the checks can reveal

A required field is blank

A row without a product name, SKU, or price may be rejected, skipped, or imported with incomplete details. Confirm which fields your catalog requires. Ask the supplier for missing values instead of filling them with guesses.

The same code appears more than once

A repeated SKU can mean an accidental duplicate, but it can also point to separate variants or locations. Compare the description, size, color, and other identifying fields first. Remove a row only when you have confirmed that it is genuinely repeated and unnecessary.

Prices or quantities use different formats

One row may show a decimal point while another uses a comma, or a price may include a currency symbol while others do not. The importer may read these values differently. Check the expected number format, currency, and unit before mapping the column.

Columns contain mixed kinds of information

A price column that includes notes such as “call for price” is not a clean numeric field. A quantity column might mix numbers with words such as “in stock.” Decide how the catalog handles those cases, then correct the source data or request a consistent file.

The importer reports an encoding or delimiter problem

Unusual characters in names, or a whole row appearing inside one column, can indicate that the file is being read with the wrong text encoding or separator. Check the supplier's export settings and your import options. For background, see how to check a CSV file's encoding before import.

How to fix common import problems

1. Confirm the import requirements. Check the catalog's required columns, accepted formats, and field names before editing. This prevents you from changing a supplier file into a format the importer does not expect.
2. Keep identifiers as text. Treat SKUs, UPCs, and supplier codes as labels, not numbers. If a code has leading zeros, preserve them exactly. Do not invent a replacement code when the original is missing.
3. Normalize values consistently. Make sure prices use one decimal style and a known currency, and that quantities use a consistent unit. Keep notes and descriptive text out of fields intended for numbers.
4. Investigate repeated rows before removing them. Sort by the relevant identifier, compare the full row, and confirm whether repeated records are duplicate products or legitimate variants. The CSV Editor can remove duplicates, but the right choice depends on the data and the import rules.
5. Check product names and descriptions. Look for extra spaces, inconsistent capitalization, broken characters, and supplier notes that should not appear in your catalog. Search for known problem words or values, then correct only what you can verify.
6. Verify image links and categories. Check that image fields contain links in the format the importer accepts, and that category names match your catalog's allowed values. A plausible-looking link or category may still point to the wrong product or fail to match.
7. Test a small import first. If the catalog allows it, import a few representative rows, including a variant and a product with a longer description. Review the resulting names, prices, identifiers, and images before importing the full supplier file.

Keep a clean source file

Save a dated copy of the original supplier CSV and a separate corrected copy. That gives you a way to compare changes, repeat the import, or ask the supplier about a questionable value. Record any mapping choices, such as which supplier code matches your SKU, so the next delivery is easier to review.

The CSV Editor works in your browser, and files you open stay on your device.