How to Use Package Sets for Multi-Package Shipments
Updated
Yes. ShipStation stores multi-box configurations as Package Sets — the number of packages and the dimensions, weight and insured value of each — and applies them to one order or to a whole selection at once. If a particular order shape always ships as two 12×12×12 cartons and one long box, that is saved once and applied with two clicks thereafter.
Since 2026 there is a second answer worth knowing about. Packing Recommendations computes the packing plan itself from your product dimensions and your configured packages, and — applied by its own automation rule action — creates the multi-package configuration at import without anyone opening the order.
Between them they cover most of the manual work in multi-box shipping.
What a multi-package shipment actually is
One shipment containing several packages. It gets a master tracking number and a child tracking number per box. ShipStation notes it counts as one shipment for fees and shipment limits, which matters if your plan is banded on shipment volume.
This is distinct from splitting an order into several shipments, which produces genuinely separate records. The choice between them is not stylistic and it is largely made for you by the carrier, as below.
Which items go in which box
A multi-package shipment can now record what’s in each box, not just the boxes. In Package Configuration, add your packages from your saved ones or by typing dimensions, adjust the quantities, and drag items to each package. One order line can be divided across boxes.
ShipStation treats this as optional, but it’s worth doing when your packers need to know what goes where, because a packing slip can then print one section per package. Packing Recommendations fills in the assignment for you.
Packing Recommendations, if you would rather not decide
Package Sets assume you already know the configuration. Packing Recommendations works out the configuration for you, and if you are hand-building multi-package shipments today it is the first thing to turn on.
ShipStation describes it as automatically recommending the best package configuration for an order based on your product dimensions, weights and available packages, returning a plan that uses the fewest packages needed. Since October 2026 it is applied by an automation rule action, Recommend Package, so once you add the rule ShipStation creates the multi-package configuration at import on the orders it matches. You can edit the result afterwards.
Two prerequisites, both of them things worth having anyway:
- Dimensions and weights on your products
- Custom packages configured with dimensions and a maximum weight
One caveat. It solves for fit, the fewest packages that hold the order. Once dimensional weight applies, two or three smaller boxes can occasionally bill less than the fewest-boxes plan, and it won’t choose them. Put its rule above any Set Rate Shopper rule so the plan is what gets priced. The wider picture on automated splitting covers where that sits.
The carrier limits
Three of these decide whether the feature is available to you at all.
USPS does not support multi-package labels. Not a low limit — none. For USPS volume the mechanism is splitting the order into multiple shipments instead, which is a different flow with different records.
FedEx One Rate does not support multi-package shipping. If you use One Rate, this is a per-service exclusion rather than a per-carrier one.
Multi-package is not available for return labels. If an inbound return needs several boxes, that is separate return labels from a split order.
Where it is supported, ShipStation publishes the caps. These are carrier limits as of August 2026 and they change:
| Carrier | Maximum packages per shipment |
|---|---|
| UPS | 20 |
| FedEx | 100 |
| DHL Express | 999 |
If the carrier and service you have selected does not support it, ShipStation displays a warning inside the Multi-Package Shipment editor rather than failing at label creation.
That warning helps when someone is building the shipment in the editor. It matters more now that Recommend Package builds multi-package configurations automatically. If Rate Shopper chooses the service, it will not pick a service that cannot carry a multi-package label, so the two do not collide. If the service is pinned before that — by Service Mapping from the customer’s checkout choice, by a static rule, or by hand — an order can arrive at the label with a multi-package configuration its service does not support, and label creation fails.
Building the shipment
Click + Add Package next to the Package dropdown and the Multi-Package Shipment editor opens. Set dimensions, weight and insurance for the first package, then either Add Package for a new one or Duplicate for an identical one. There is a dropdown that adds five, ten or fifteen at once, which is the difference between usable and not on a pallet-adjacent order.
Tick Save New Package Set on the way out and the configuration is stored.
Sets can also be built up front, without an order in front of you: Settings → Shipping → Packages → Package Sets → Add Package Set. A set holds the number of component packages and the dimensions, weight and insured value for each.
Applying one
Three ways, and the third is the one that pays.
On a single shipment, pick the set from the Package dropdown.
Apply and then modify, by opening the Multi-Package Shipment popup, choosing Apply Package Set, and then changing what needs changing. This is the common case — a saved configuration that is right for four of the five boxes.
In bulk, by selecting orders in the grid and choosing Package from the Bulk Update menu, then picking the set. This is the version worth building for. If you have a recurring order shape — a subscription tier, a wholesale case pack, a seasonal bundle — filtering the grid to it and applying a set to the whole selection turns a per-order task into a per-batch one.
Three limits on the sets themselves
You cannot edit a saved Package Set. ShipStation states this directly: you can delete one and reuse the name, but there is no edit. So treat a set as disposable rather than as configuration you maintain, and do not build twenty of them expecting to tune them later.
Only one set per shipment. You can add further packages manually on top of an applied set, but you cannot combine two sets.
Insurance is per package and the shipment-level field is disabled. On a multi-package shipment ShipStation greys out the Insured Amount field and requires a value on each package inside the editor. A Package Set can carry those values, which is the only way to make insurance on multi-box orders anything other than manual — no automation rule reaches into a multi-package configuration.
What you lose by shipping this way
These are the ones that generate support tickets, and none of them are visible when you create the label.
Your customer gets one tracking number. Each box has its own, but only the master appears in the Tracking # column, and the master is what goes to the marketplace and into the shipment notification email. ShipStation says outright that to send the additional tracking numbers to your customers, you must do so outside ShipStation.
For a customer expecting three boxes, one tracking number that shows delivered when one carton arrived is a support contact you will receive. It is worth deciding in advance whether you tell them, and how.
Voiding is all or nothing. To void a multi-package shipment you void the master tracking number, which cancels every child label. There is no way to void one box. You then rebuild the whole shipment to get new labels and new tracking numbers. If a single carton is damaged during packing, that is the cost.
You cannot describe the boxes. ShipStation states you cannot customise descriptions for Package #1, Package #2 and so on. If your operation relies on “box 2 of 3 contains the manual and the hardware”, that has to live on the packing slip or on a physical label, not in ShipStation.
International adds a per-parcel field. Shipments to Mexico require a 35-character Package Description for every parcel, and the field appears per box inside the Package Set popup. That is one of several destination-specific requirements that only surface on the form.
One thing you do keep: the Rate Browser shows rates for multi-package shipments, so you can still compare before committing.
Where this sits against the real problem
Package Sets speed up the execution of a decision, and Packing Recommendations now makes a good version of the decision on every order its rule matches.
What it leaves is the comparison on cost. Cartonization is a bin-packing computation rather than a rule, and Auto-Split divides an order on product attributes you declared in advance rather than on fit. Packing Recommendations closes the computation for fit; where dimensional weight makes a different set of boxes cheaper, it still returns the fewest.
So the honest positioning of Package Sets is this: if your multi-box orders are a small number of repeating shapes, sets convert that from a daily typing task into a bulk action, and that is a genuine saving. If your multi-box orders are all different, sets will not help, because you will be building a new one each time and the editor is the same either way. That case is what the packing rule is for, provided the catalogue carries dimensions.
Which of those you are is answerable from your own data. Export the shipments that had more than one package and count the distinct package configurations. A handful of shapes covering most of the volume means build the sets. A long tail of unique ones means the problem is upstream.
What to check
Look at your multi-package volume by carrier first. If most of it is USPS, none of this is available and the conversation is about splitting orders instead.
Then look at whether those shipments carry insurance. On multi-box orders it is manual, per package, and it is the thing most likely to have been skipped under pressure.
What this does not fix
A saved package configuration is a record of a decision someone made once. If that decision was wrong — three boxes where two would have done, or a carton size chosen because it was on the shelf — the set makes the wrong answer faster and permanent.
Worth checking the configurations you save before you save them, because the box is what you are billed on and a set applied in bulk multiplies whatever is in it.
For operations past what rules can do
When a saved set isn't the right answer
Pro Automation works out the boxes for each order rather than applying one you saved.