Home › Merge Guides › Shopify + BigCommerce › Inventory Reconciliation

Merge Shopify and BigCommerce Sales Data for Inventory Reconciliation

Matching units sold against inventory counts requires the same product and quantity columns across every channel's export.

Why Shopify and BigCommerce exports don't line up

Shopify: a Created At timestamp that includes a timezone offset; a single Total column that already nets out discounts, with tax broken out separately; an order Name like #1001 rather than a numeric ID. Also, exports one row per line item by default, so an order with 3 products becomes 3 rows unless you export the summary report instead.
BigCommerce: an Order Date column that includes a full timestamp; Subtotal and Grand Total both included, which are easy to mix up when mapping; a numeric Order ID. Also, many optional columns are exported blank depending on store configuration, which can throw off auto-mapping by header position.

For inventory reconciliation, that mismatch is exactly what causes hours of manual cleanup every period.

Open CSV Experts and set your target columns once (Date, Channel, Order ID, Total).
Drop in your Shopify export and map its columns once.
Drop in your BigCommerce export and map it the same way — both merge into one sheet, normalized.
Export as CSV or Excel. Same-layout files merge automatically next time.

No. Everything runs in your browser using JavaScript — your files are never sent to a server.

Yes. Add as many source files as you want; each distinct file layout is mapped once and remembered.