Planning peak season with your 3PL, from eight weeks out to January.

Plan peak backwards from the carrier dates, in writing, with your 3PL. Eight weeks out you send a forecast by SKU and by week and book inbound dates; four weeks out the stock and the packaging are on the shelf; two weeks out you publish your ship-by dates; in the first week of January you work the returns wave and count what is left. Three things change in peak, your volume, the carriers’ calendar and surcharges, and your 3PL’s SLA and rates, so get all three on paper before Thanksgiving week.

The timeline, from eight weeks out to the first week of January

A 3PL plans labor from your numbers. A forecast by week with the sale dates marked becomes pickers on the floor on the right days; a sale nobody told the warehouse about becomes a backlog. The table runs on the 2026 calendar: Thanksgiving is Thursday, November 26, Black Friday is November 27, Cyber Monday is November 30, Christmas is Friday, December 25. With four weeks left, do the eight-week and six-week rows this week, in order. The rows compress. They do not skip.

Forecast by SKU and by week, then book the inbound and the packaging

A peak forecast is not a total. It is a list of SKUs with a number for each week from Black Friday to the carrier ground date, built from last peak’s orders and scaled by what has changed: the promo calendar, a new channel, the stock you can get. Say twenty SKUs carried most of last December’s units. Those twenty get a weekly number and a reorder point; the rest get a sanity check. First peak: use your last three months of orders and say so. Send it as a file. The first thing a warehouse does with it is plan pickers by day.

Inbound is where peak plans slip. Suppliers run late, freight gets bumped, and a receiving dock in November has a queue. Book inbound dates when you place the purchase orders, and send carton counts and SKUs per carton ahead of the truck. A labeled inbound, one SKU per carton with a packing list, takes fewer receiving hours than a mixed pallet, and at YNK receiving is billed hourly. How to send inventory to a 3PL has the checklist. Agree a last inbound date and give it to your suppliers as their deadline.

Packaging runs out before stock does. Count what one peak order uses: carton or mailer, tissue, insert, gift box, tape, dunnage. Multiply by the forecast, add a buffer, and have it on the warehouse shelf four weeks out, shipped like inventory with a packing list. At YNK packaging and supplies are billed as used, and your own boxes and inserts are stored and packed to your spec.

Carrier ship-by dates and demand surcharges, as of October 2026

Both change every year, so read the carrier’s current page. For delivery before December 25, USPS recommends sending by Thursday, December 17 for USPS Ground Advantage and First-Class Mail, Friday, December 18 for Priority Mail, and Saturday, December 19 for Priority Mail Express, checked October 26, 2026; the page calls these recommended dates and says actual delivery can vary. FedEx’s 2026 deadlines sheet targets arrival by December 24 and sets the last ship day for FedEx Ground and Home Delivery by transit time: December 17 for a five-day transit, December 18 for four days, December 21 for three, December 22 for two and December 23 for one, with FedEx 2Day on December 22 and the overnight services on December 23, checked October 26, 2026, assuming a regular scheduled pickup or a staffed-location drop-off.

Transit time is the part brands miss. From Elmwood Park, ground reaches the Northeast in one to two business days and goes coast to coast in about five, so a West Coast customer’s ground deadline is the five-day date, December 17, with the order in by 12pm ET to ship that day. Build your cutoff from your warehouse’s location and the carrier table, then take a day off it.

Carrier holidays matter too. FedEx lists Thanksgiving Day, November 26, as closed, with modified service on the 25th and 27th, modified service on December 24 and 31, and closed on December 25 and January 1, checked October 26, 2026. An order placed on the evening of the 24th is not late. It ships on the next day the carrier picks up.

Demand surcharges are per-package amounts the carriers add during peak. As of October 26, 2026, FedEx adds $0.50 per package on Ground Residential and Home Delivery residential shipments from October 26 to November 22, $0.80 from November 23 to December 27, and $0.50 again from December 28 to January 17, 2027, with the demand Additional Handling surcharge at $8.80 per package from September 28 and $11.85 from November 23 to December 27, and the demand Oversize charge at $95.75 and $117.25 on the same dates. USPS added a temporary peak increase on Priority Mail Express, Priority Mail, USPS Ground Advantage and Parcel Select for October 4, 2026 through January 17, 2027, from $0.40 per piece on commercial Priority Mail and Ground Advantage in zones 1 to 4 up to 3 pounds, and confirmed the prices took effect on October 4, both checked October 26, 2026. If you ship UPS, ask your 3PL for its current peak schedule and read it the same way.

A carrier surcharge is not a 3PL surcharge, and the second is the one to ask about: whether the 3PL adds anything of its own on handling or storage for the season, and how carrier surcharges appear on your postage invoice. That line usually sits in a schedule, not on the rate card; the hidden 3PL fees checklist shows where to look.

What to tell customers, and when

Customers forgive a date they were told, not a date they assumed. Put the ship-by dates on the product page, in the cart and in the order confirmation, and change the banner on each carrier date. Three messages cover the season.

1. 01Before the ground date: order by your date for delivery before Christmas with standard shipping. Use your real date, from the carrier table and your warehouse’s transit times.
2. 02Between the ground date and the overnight date: standard shipping now arrives after Christmas; expedited is available at checkout.
3. 03After the overnight date: orders arrive after Christmas. Say it plainly and sell gift cards.

State the same-day cutoff too. A site that says ships same day without the cutoff time is making a promise the warehouse did not make.

What peak looks like on our floor

Orders in by 12pm ET ship the same business day, in peak as in June. The SLA on orders after the cutoff moves from one business day to two to three, and that is the only term that moves. Handling stays at an estimated $3.00 per order, storage at $0.65 per cubic foot per month, returns at $3.00 per parcel. There are no seasonal or peak surcharges on handling or storage; your rate in December is your rate in June. Postage is billed semi-monthly per shipment, itemized, so each line is one parcel you can trace to one order.

Labor is planned from your forecast: tell us the date and the expected volume and we staff for it. Nominal, a jewelry brand on our floor, called a warehouse sale at the last minute, with no peak plan and no labor booked ahead. The sale put 10,000+ orders on the floor in one weekend, and every order shipped within SLA, with no surcharge on handling or storage and no renegotiation. The operators who run our own brands through peak ran that weekend, and every order and pick was visible to the brand in the same WMS we use. With a forecast in hand, that weekend is a plan rather than a save.

Every major carrier picks up from Elmwood Park daily. Hours are Monday to Friday, 9am to 6pm ET; weekend and holiday shipping is set case by case in your agreement, so ask for it in the proposal if your sale lands on a Saturday. You watch the queue on the same dashboard we do: live inventory, order status, SLA tracking. How fulfillment at YNK runs covers the setup; most brands are live in under two weeks, and the intake takes about ten minutes.

The returns wave and the January count

Returns from peak purchases arrive after Christmas, and they arrive together. Set the rules before the sale: what gets restocked, what gets set aside, when the refund fires. At YNK returns come back to the same floor, each parcel is received, graded, then restocked or set aside per your policy, and refunds can fire on receipt through your store, at an estimated $3.00 per parcel. Forecast returns next to orders. How 3PL returns processing works covers grading.

January is also when the cube drops. Storage is billed on the cubic feet you use, so as peak stock sells through, the storage line falls with it. What did not sell holds its cube at $0.65 per cubic foot per month while it waits, so decide in the first week of January, SKU by SKU: keep selling, bundle, mark down, or pull. Then run the post-peak review: SLA by week, error rate, which SKUs stocked out and when, packaging used against what you ordered, postage per order from the itemized invoice. That review is next year’s forecast.

The peak checklist

• Forecast by SKU and by week, Black Friday to the carrier ground date, sent as a file.
• Promo calendar with every sale date and expected volume, sent the day it is set.
• In writing from your 3PL: peak SLA, rates, any seasonal surcharge, cutoff, holiday operating days, last inbound date.
• Purchase orders placed and inbound appointments booked, one SKU per carton, carton counts sent ahead.
• Packaging for the forecast plus a buffer on the warehouse shelf four weeks out.
• Kits built as SKUs, gift-note and insert rules written down, catalog frozen.
• Ship-by dates on the site, in the cart and in the order confirmation, with a rule for orders placed after the ground date.
• Returns rules set, returns forecast next to the order forecast, post-peak review booked for the first week of January.

Questions brands ask about peak season