A carton marked “accessories” can contain several colours, sizes and product models. That description may be enough for someone who packed it yesterday. It is much less useful to a receiving team opening the carton after an international shipment. Without a map between the outer package and its contents, checking stock becomes a search through every box.
A mixed-carton SKU map records which products belong in each shipping carton. It allows a buyer to check quantities before dispatch and lets a warehouse identify shortages without losing the relationship between products and packages. The process works with a simple spreadsheet as long as carton identities remain stable and revisions are controlled.
Choose two separate identifiers
Use a product identifier for the item and a carton identifier for the package. They answer different questions. The SKU identifies what the product is; the carton number identifies where it was packed. A carton can contain several SKUs, while one SKU can appear in several cartons.
For example, a hypothetical order might use SKU-BLUE-S for a small blue item and carton C014 for one outer package. Avoid naming the carton “BLUE-S” if it also contains other products. Otherwise, the label encourages the receiving team to make the wrong assumption before opening it.
An internal carton code does not automatically constitute an official barcode or a globally unique identifier. If a customer or warehouse requires a particular identification standard, agree on that requirement before printing labels. The GS1 identification keys reference provides background on standard identifiers; internal worksheet codes should not be presented as GS1-issued numbers.
Use one row per carton and SKU combination
A practical table has columns for carton ID, SKU, product description, variant, quantity, unit of measure and order reference. Repeat the carton ID across rows when several SKUs share the same box. This is easier to total and filter than putting a long list of products inside one spreadsheet cell.
Keep the unit of measure explicit. “Quantity 12” could mean twelve pieces, twelve pairs or twelve retail packs. If a pack contains several saleable pieces, record the pack structure separately rather than silently mixing units in the quantity column.
Add the supplier's product reference alongside your internal SKU when they differ. A warehouse should not have to infer that the supplier's model X7 corresponds to your own catalogue code. Use a description that distinguishes similar variants without relying exclusively on a photograph.
Check a worked quantity example
Suppose an illustrative order contains 30 blue items and 20 grey items. Carton C001 contains 12 blue items and eight grey items. Carton C002 contains 18 blue items and twelve grey items. The map therefore has four rows, even though the shipment has only two cartons.
Summing by SKU gives 30 blue and 20 grey, which matches the order. Summing by carton gives 20 units in C001 and 30 in C002. These two checks serve different purposes: one verifies the commercial quantity, while the other helps the receiving team count each package.
If the supplier moves two grey items from C002 to C001, the order total still matches. A check of SKU totals alone would miss the change. The carton-level quantities must also be updated so the warehouse does not incorrectly report a shortage in C002 and an overage in C001.
Keep labels and the map synchronized
Print or write the carton ID clearly on the outer package and use the identical value in the map. Avoid small differences such as C-014 in one place and C014A in another. If the identifier changes during repacking, record which old carton became which new carton.
A photograph should show the carton ID and the sealed package together. For a mixed carton, an additional packing-stage photograph can help identify the grouping of items. It supports the record but does not replace a count. A photograph of the top layer cannot prove the contents underneath it.
Send the final map together with the current packing list. If several suppliers contribute to a consolidated shipment, include a supplier prefix or another agreed method of avoiding repeated carton numbers. The shipping overview explains the wider handover context in which this information is used.
Handle repacking without losing the trail
Repacking can improve handling or separate damaged packaging, but it changes the relationship between original and final cartons. Create a short repacking record with the original carton IDs, new carton IDs, transferred quantities, date and responsible person. Mark the superseded map clearly.
If one original carton becomes two new cartons, do not leave all three listed as active packages. If two cartons are combined, preserve the original references in a notes column so a later supplier question can still be traced back to the dispatch record.
Before booking or final warehouse handover, reconcile the active carton count with the outer-package count used for the quotation. Product quantities and package quantities should both be correct, but they are not interchangeable. A map that totals the products correctly can still omit a whole outer package from the freight information.
Use the map during receiving
Give the receiving team the latest revision before arrival. Count sealed outer packages first, record visible exceptions, and then check contents against the relevant carton rows. Keep unresolved differences attached to the carton ID instead of adjusting the overall stock total immediately.
If C001 is missing two grey items, record that specific difference and preserve the packaging evidence. Check whether the two items appear in another carton before concluding that the supplier shipped fewer units. Mixed-carton mapping helps distinguish a packing-location error from an actual quantity shortage.
After the check, retain both expected and received quantities. Overwriting the expected column removes the baseline needed for investigation. The English guide library contains related planning material, but the essential output here is one reliable relationship: every received unit can be connected to a product identity, an outer carton and the version of the packing record used at dispatch.