3PL vs in-house fulfilment: when to outsource

Nearly every growing brand hits the same evening: orders are up, the packing table is now three tables, and somebody is still taping boxes at nine o’clock. The question arrives on its own — do we keep doing this ourselves, or hand it to a third party?

The honest answer is that both models are correct at different stages, and the switching point is narrower than most advice suggests. What follows is how to work out which side of it you are on.

What each model actually means

In-house fulfilment means you hold your own stock, in your own space, packed by your own people. You own the process end to end, including the parts that go wrong at 4pm on a Friday.

A 3PL — third-party logistics provider — stores your inventory in their warehouse, picks and packs against orders pulled from your store, and ships using their carrier contracts. You keep the brand and the inventory; they run the operation.

The distinction that matters is not “outsourced or not”. It is which of your scarce resources the model consumes: in-house consumes your team’s attention and your space; a 3PL consumes cash per order and some control.

The real cost of doing it yourself

In-house fulfilment looks cheap because most of its costs are already on your books under other names. Count them properly:

• Space. Rent, service charge, insurance, heating — and the fact that stock expands to fill whatever you give it.
• Labour. Not just packers, but the founder-hours spent on rotas, cover and supervision, which are your most expensive hours.
• Shipping rates. Your carrier pricing at 300 parcels a month is materially worse than a 3PL’s at 300,000. This is often the single biggest line.
• Packaging bought in small quantities, at small-quantity prices.
• Equipment — scanners, printers, scales, shelving, a label printer that jams.
• Peak. Temporary staff, overtime, or a founder losing December.
• Error cost. Mis-picks, replacements and the goodwill spent on them.
• Opportunity cost. The most expensive item, and the one never on a spreadsheet: what your team did not do because they were packing.

Under roughly 200–300 orders a month, in-house usually still wins on total cost, because a 3PL’s per-order fees exceed the marginal cost of your existing space and people. Between 300 and 1,000, it depends on your product and your team. Above about 1,000 a month, the shipping-rate difference alone often covers the 3PL’s entire fee.

Treat those numbers as orientation, not law — a brand shipping bulky furniture crosses over far earlier than one shipping envelopes.

Where in-house genuinely wins

Outsourcing is not automatically the grown-up choice. Keep it in-house when:

• The unboxing is the product. Hand-finished packaging, handwritten notes, ribbon tied a particular way. Some 3PLs support this well; many charge per touch until it stops making sense.
• You are still changing the product weekly. Early-stage brands iterating on packaging and inserts move faster with the stock in the room.
• Volume is low and irregular. Monthly minimums punish quiet months.
• Assembly is genuinely bespoke. Complex custom configuration per order can be cheaper to keep close.
• You are learning. There is real value in packing your own orders for a while. You learn which SKUs are awkward, which packaging fails, and what customers write on returns slips. That knowledge makes you a better client later.

Where a 3PL wins

• Carrier rates. Aggregated volume buys pricing you cannot get alone.
• Peak absorption. November stops being a staffing crisis and becomes a forecast you send.
• Speed to customer. A well-positioned warehouse reaches more of Europe in one day than your unit does. See e-commerce fulfilment and EU distribution.
• Cut-off times. Professional operations dispatch later in the day than a team that also has other jobs.
• Systems. Barcode-driven picking, stock accuracy and audit trails — hard to replicate on a spreadsheet.
• Focus. Your team goes back to product, brand and demand.
• Multi-channel. Selling on your own store plus marketplaces plus wholesale gets complicated quickly; allocation is what warehouse systems are for.

Cost comparison at a glance

Note the first row, because it is the one that decides the argument. In-house costs are largely fixed, so cost per order falls as you grow — until you hit a wall and must add space and people in a step. A 3PL is largely variable, so cost per order is predictable and scales smoothly. Which shape you want depends on how confident you are in your growth.

The signals it is time to switch

Rather than watching a threshold, watch for these:

1. You are shipping late. Orders leaving in two days that should leave same day is a capacity problem you have already lost.
2. Stock accuracy is drifting. If a count surprises you, you have outgrown your system.
3. Peak damaged something. Missed dates, burnt-out staff, refunds.
4. You are quoting delivery times you know are optimistic.
5. Your best people are packing. If a founder or senior hire is on the packing table weekly, the real cost is enormous and invisible.
6. You are about to sign a bigger lease purely for stock. Compare that lease against a year of 3PL fees before you sign.
7. Cross-border is becoming significant. Once meaningful volume goes to other EU countries, warehouse position and VAT reporting start to matter.

Making the transition well

If you decide to move, sequence it deliberately:

• Do not switch during peak. Move in your quietest quarter.
• Barcode everything at source. Un-barcoded stock has to be labelled on arrival, at your cost, and it is the commonest delay.
• Clean your product data first. Dimensions, weights, SKUs. The 3PL’s system is only as good as what you give it.
• Run parallel briefly if you can — keep a small buffer in-house for a few weeks so a hiccup does not mean a stockout.
• Agree the SLA in writing. Cut-off times, accuracy, dispatch confirmation timing, who pays for errors, peak commitments.
• Keep your reason codes. Insist that returns come back with an analysable reason, so you keep learning what you learned when you packed yourself.

The hybrid nobody mentions

You do not have to choose absolutely. Common workable splits:

• 3PL for direct-to-consumer, in-house for wholesale and events, where bulk orders need bespoke handling.
• 3PL for the core range, in-house for limited drops you want to finish by hand.
• 3PL for one region, in-house for your home market, where you can deliver well anyway.

The overhead is running two sets of stock, so it works best when the split is clean by channel or product rather than blurred.

Frequently asked questions

At what order volume should I move to a 3PL? As orientation, in-house usually still wins below 200–300 orders a month, and a 3PL usually wins above roughly 1,000. Between those, model it against your own shipping rates, space costs and how much founder time fulfilment consumes.

Is a 3PL more expensive than doing it myself? Per order, often yes on the invoice — but the comparison must include your space, labour, carrier rates and peak costs. Once carrier discounts are counted, many brands find the total is lower at moderate volume.

Will I lose control of the customer experience? You lose direct handling, not control. Specify packaging, inserts and standards contractually, approve a packed sample before go-live, and audit periodically by ordering from your own store.

Can I keep custom packaging with a 3PL? Yes, though each additional manual step is usually priced per order. Design the unboxing so it is repeatable rather than artisanal — see custom packaging.