Rate Changelog

Launched the recurring monthly carrier benchmark system. The evergreen hub at /blog/which-shipping-carrier-is-cheapest-updated-monthly-analysis/ now points at the current issue. August 2026 content is archived at /blog/cheapest-shipping-august-2026/. September 2026 is published at /blog/cheapest-shipping-september-2026/. Dataset 07 adds downloadable CSV/JSON snapshots at /data/monthly-benchmarks-latest.*, /data/monthly-benchmarks-2026-08.*, and /data/monthly-benchmarks-2026-09.*. September is a rerun against the current verified config: no new published USPS, UPS, or FedEx base-rate table was logged this month.

Final HTS/import tie-break polish: ranking now prefers commercially specific HTS8 rows over close HS6 fallbacks and nearby families on phone case, ring light, car seat cover, food storage container, and stroller organizer queries. Dataset 05 mappings stay row-level on those same specific lines. HS6 fallbacks remain where an 8-digit line would over-claim. Expanded the US HTS planning lookup dataset (/hts-code-lookup/ and /data/hts-us-lookup.*) from the 53-row launch baseline to over 300 planning rows covering mainstream ecommerce categories, with structured HS6 fallback support so broad queries return safe headings without fake precision. Replaced the flat monolithic 12% apparel default on /hs-duty-estimator/ with distinct planning buckets (Cotton knit 16.5%, MMF knit 32%, Woven cotton 16%) and a dedicated unclear-apparel option directing users to HTS lookup or manual entry. Added Dataset 05 (/data/china-additional-duties.*) providing row-level Chapter 99 / Section 301 planning mappings where specific support exists; handoff from HTS lookup to /hs-duty-estimator/ can prefill additional duty overrides for mapped rows only while remaining fully user-editable. Added Dataset 06 (/data/us-import-entry-fees.*) exposing public, citable reference rows for core US import entry fees and port charges: Merchandise Processing Fee (MPF, 0.3464% with FY2026 $33.58 min / $651.50 max limits across all formal modes) and Harbor Maintenance Fee (HMF, 0.125% ad valorem with explicit ocean-vessel-only mode scoping). Tightened verification-sensitive HTML and data route cache policies (max-age=0, s-maxage=3600, stale-while-revalidate=3600) to eliminate multi-day stale edge cache behavior across /hs-duty-estimator/, /hts-code-lookup/, /data/, and /changelog/.

Updated import duty modeling on /hs-duty-estimator/: narrowed Regulation (EU) 2026/382 temporary €3 low-value customs duty treatment to an opt-in toggle (default off) with explicit legal scope (1 July 2026 to 1 July 2028 for qualifying low-value consignments up to €150) rather than blanket parcel application; updated formal-entry Merchandise Processing Fee (MPF) to FY2026 CBP user fee schedules ($33.58 minimum, $651.50 maximum at 0.3464% FOB value); removed blanket automatic 25% China Section 301 add-on in favor of user-entered additional duty override (Chapter 99 / Section 301) and explicit classification advisory; removed stale GSP label on Bangladesh. Added /hts-code-lookup/ (US HTS planning search; CSV/JSON at /data/hts-us-lookup.*; no carrier rate-table change). Published Open Rate Data hub at /data/ with downloadable CSV and JSON datasets for DIM weight rules, carrier handling and surcharge triggers, and Notice 123 USPS Cubic tiers (Version 2026-Q3 snapshot). Added /commercial-invoice-generator/ (CN22, CN23, commercial invoice PDFs built in the browser; no rate-table change). Added /how-to-ship/ hub and 24 item guides (content only; no rate-table change). Couch, mattress, and treadmill blog URLs 301 to /how-to-ship/. Added carrier-specific DIM landing pages at /ups-dim-weight-calculator/, /fedex-dim-weight-calculator/, and /usps-dim-weight-calculator/. They lock the existing DIM engine; no divisor or rate-table change. FedEx DIM remains a 139 model until a 2026 FedEx Rate Guide PDF is independently verified. Also: Oversize & Additional Handling Surcharge Calculator at /shipping-surcharge-calculator/. USPS nonstandard length and volume fees use Notice 123 commercial amounts effective July 12, 2026. UPS and FedEx Additional Handling / Large Package dollar amounts are not stored until a dated rate-guide cell is logged; thresholds still evaluate. USPS Cubic maximum dimension update (effective July 12, 2026): maximum side length for both Priority Mail Cubic and Ground Advantage Cubic increased from 18 inches to 22 inches.

Source: USPS Postal Explorer (pe.usps.com) — Domestic Mail Manual cubic-pricing eligibility and Notice 123 rate tables. Verify the current DMM and Notice 123 on Postal Explorer before making a shipping decision.

USPS Ground Advantage dimensional weight divisor updated from 166 to 139 for parcels exceeding 1 cubic foot (1,728 cubic inches). Dimensional ceiling rounding (rounding every fractional inch up to the next whole integer before calculating volume) instituted per DMM 283 §§1.4.1–1.4.2. Notice 123 commercial rate tables updated across all zones.

Source: USPS Postal Explorer (pe.usps.com) — Domestic Mail Manual (DMM 283) and Notice 123 commercial price schedules.

UPS residential delivery surcharge updated to $6.60 per package for ground shipments to residential destinations. Applied in shipping cost comparison engines.

Source: UPS Rate and Service Guide — Value-Added Services and Additional Charges schedule.

Public site launch date: June 20, 2026. Initial DimMath launch rates, divisors, and FBA fee tables as recorded at launch. Some entries below record historical source-effective dates that were already loaded into the launch configuration and therefore predate the public launch. Confirm current DIM rules and published prices against carrier guides before shipping.

Amazon implemented a 3.5% fuel and logistics surcharge applied directly to base FBA fulfillment fees across all standard and bulky size tiers. Integrated into FBA fee and landed cost calculations.

Source: Amazon Seller Central — Fulfillment by Amazon 2026 fee policy update.

Full 2026 Amazon US FBA fulfillment fee schedule effective date. Includes updated size tier thresholds (including Small Bulky tier for items 18–37″ length, ≤ 24″ median, 20–50 lbs), referral fee schedules, low-inventory fee brackets, and storage rates ($0.87/cu ft standard, $2.40/cu ft Q4).

Source: Amazon Selling Partner News — 2026 US FBA fulfillment fee and size tier schedule.

Annual general rate increases took effect (UPS effective December 22, 2025; FedEx effective January 5, 2026), applying an average 5.9% increase across base commercial and residential ground rate tables.

Source: UPS & FedEx Published GRI Notices — Annual carrier general rate increase announcements.