09/25/2026
Peak season is not only "extra fees start in late September." The quiet killer for Shopify self-fulfill brands is which economy service you pick for light residential packages.
In 2026 peak windows, FedEx Ground Economy and UPS Ground Saver sit in the same job - cheap residential ecommerce - but the per-package demand surcharge spreads are nowhere near the same. That gap shows up order after order while your pack station still looks busy and "fine."
USPS is the structural outlier again: it raises the published price on Priority Mail, Ground Advantage, Express, and Parcel Select from Oct 4 into mid-January, instead of adding a separate surcharge line you can spot on the invoice.
If you self-fulfill, model the mix before the truck leaves: carrier, service, weight, zone, and anything near additional handling. Rates belong on the pack screen, not in a spreadsheet you update after peak is over.
Sources: carrier peak notices and the 2026 peak surcharge roundups (UPS / FedEx / USPS).