A bin location is a short label - A4, W-12, Back wall - recording where an item physically lives. Stockroom keeps one per variant, with per-location overrides for stock that's shelved differently in each place, and shows it wherever someone would go looking for the item.
Set bins on the product page
Open a product and find the Costs & replenishment section. Each variant row has a Bin field. The Default row is the one every location falls back to; pick a location above the table to give that location its own bin, and location rows show the inherited default greyed out until you type over it. The Combined tab sets reorder levels across your locations and carries no bin - a shelf belongs to a building.
An item can hold more than one shelf: next to the Bin field, Overflow opens a small editor for up to 5 extra bins - useful when a pick face like A4 is restocked from bulk in R12. The Bin field stays the pick face, and everything that prints or prefills a bin keeps using it; overflow bins count into the Products list's "+2" style rollup, and ride the stock-settings CSV in an extra_bins column (separated by semicolons). One nice side effect while receiving: putting a delivery away in a shelf the item already lists - pick face or overflow - changes nothing, so stocking the bulk bin never flips the pick face.
Set bins while you put a delivery away
The moment you actually know where something goes is when you are holding the box. On the receive card, open the Columns picker and switch on Bin: every line gets a bin field, pre-filled with whatever is already on record for that item at the location you are receiving into.
Receiving records the bin against the location the delivery arrived at. If you split one order across locations and receive it to the destinations it was ordered for, each line's bin lands at the right location on its own.
A bin you leave alone is not changed, and a field you empty does not clear the bin on record - a blank box on a long delivery means "nothing to say here", not "wipe it". The product page and the CSV are where you remove a bin.
Bins in bulk with CSV
The Inventory page's Export CSV and Import CSV carry a bin_location column alongside reorder points and supplier details, and the starter template in the import dialog includes examples. The importer also accepts bin or shelf as the header. Leave the location cell blank to set the every-location default, or name a location for its override - and blank cells never clear an existing bin, so a partial file is always safe to import. To empty a bin instead, put the word clear in the cell.
Where bins show up
Inventory - add the Bin column from the Columns picker. A product whose variants sit in different bins shows the first one plus a count, like A4 +2.
The Last counted report gains a Bin column the moment any item has one, so a counting worklist can follow the walk order of the room instead of alphabetical order. Each row shows that location's own bin when set, otherwise the default, and the CSV export always carries the column. Pair it with a stocktake when it's time to count - see Count your inventory with stocktakes.
The purchase order PDF can print a Bin column, so the printed order doubles as a put-away sheet. It's off until you switch on Bin location column in Settings, Documents & email (or for one supplier, or in the print dialog for one order), and each line prints the bin for the location that line is going to. See Customize the purchase order PDF.
Keep bins in a Shopify metafield
If another app - a picking app, your theme - reads bin locations from a Shopify metafield, Stockroom can make that metafield the bin's home. In Settings, Data & sync, find Linked metafields and pick a single-line text metafield on your products or variants for Bin location.
Linking asks one question - Where are these values today? Choose In Stockroom to copy Stockroom's bins onto the metafield, or On the metafield to bring its values into Stockroom, blanks included. From then on there is one home for the field: bins typed anywhere in Stockroom - receiving included - save to the metafield, and edits made in Shopify or another app flow back within seconds.
A linked bin is one value per item, so per-location bins stop being used - Stockroom warns you with a count before it links. A product metafield means all variants of a product share one bin; a variant metafield keeps one per variant. Unlinking keeps every bin in Stockroom exactly as it was.
Bins also drive picking: a pick list lays its lines out in bin order at the list's location, so a picker walks the shelves once. See Picking and packing orders with pick lists.
Good to know
Without a linked metafield, bins live in Stockroom only and are never written to your Shopify products.
The Bin column on the receive card is off until you switch it on, and the choice is remembered on that device. Returns have no bin column - stock is leaving.
Free text up to 100 characters. There's no bin list to maintain - use whatever your shelving already calls things.
Bins are per variant, so each size or color can have its own spot.