Preparing Products for a New Store
By Selling Fee Tools team ·
Launching a store, adding a marketplace or moving platforms all go faster when the product data is clean before you start. This checklist covers the four things most imports fail on: codes, identifiers, photos and the import file.
1. Give every variant a SKU
Every product, and every colour and size of it, needs its own SKU: your internal code that links a listing to the item on your shelf.
- One code per variant, never reused.
- Built the same way for every product, broadest part first: for example HD-0001-RED-L.
- Letters, numbers and one separator, and never starting with zero, because spreadsheets drop leading zeros.
The bulk SKU generator builds SKUs from a pattern for a whole product list pasted from Google Sheets or Excel, and makes any duplicates unique. More in how to create SKUs.
2. Check your GTINs
Marketplaces and Google Merchant Center ask for a GTIN (UPC or EAN) for most new products.
- Use the manufacturer’s GTIN, or one issued to your brand from a GS1 Company Prefix. Never make one up.
- Check the check digit of every code, and restore leading zeros a spreadsheet may have removed.
- For products that genuinely have no GTIN, such as handmade items, marketplaces have a way to say so, such as identifier_exists = no in a Google feed.
Paste the whole list into the GTIN check digit calculator to find the bad ones. More in GTIN, UPC and EAN barcodes explained.
3. Prepare photos once, for every channel
Each marketplace has its own minimum size and background rule. Amazon’s main image needs a pure white background and zooms from 1,000 px; Etsy recommends at least 2,000 px; Shopify suggests 2048 × 2048 for square images; TikTok Shop needs at least 600 × 600.
Shoot at high resolution on white, then resize a batch for each channel with the marketplace image resizer, which fits each photo on a white canvas without enlarging it. More in product image sizes for every marketplace.
4. Build a clean import file
Both Shopify and WooCommerce import products from CSV, but in different formats.
- Moving from WooCommerce to Shopify: convert your WooCommerce export with the WooCommerce to Shopify converter, then check it with the Shopify CSV validator.
- Moving from Shopify to WooCommerce: the Shopify to WooCommerce converter turns variants into variable products, converts weights to your shop’s unit and flags duplicate SKUs, which WooCommerce rejects.
- Keep the old store online until the import finishes: both platforms download product images from their URLs during import.
Before you go live
- Import a handful of products first and check them in the admin: variants, prices, stock, images.
- Set up redirects from old product URLs if you moved platforms.
- Work out your fees and margins per channel with our fee calculators before setting prices.