From 24 July 2026, the straightforward 10% flat-rate duty that many UK exporters had been using to ship goods to US customers by post has disappeared. It’s being replaced by full customs duties applied according to actual product classification and country of origin, alongside a new formal entry process — US Customs and Border Protection calls it “Entry Type 13” — designed to bring international postal parcels into line with commercial import shipments. For any UK SME selling physical products to American customers, whether through your own site, Etsy, eBay, or Amazon, this is a real change to your cost base and admin workload, not a distant policy footnote.

What’s actually changed

The core shift is that international postal shipments to the US no longer get the informal, low-friction treatment they used to. Duties are now calculated on the specific product and its country of origin rather than a blanket flat rate, which for many goods works out more expensive than the old 10% simplification — and considerably more complex to calculate correctly. On top of that, exporters will eventually need to provide detailed product information including 10-digit Harmonized Tariff Schedule (HTS) codes, and every shipment needs to be filed through a licensed customs broker acting as the Importer of Record. If you’ve been handling US shipping yourself with a simple customs form, that workflow needs to change.

Practical steps if you sell to the US

First, work out your actual exposure: pull your last three months of US order data and check what proportion of revenue depends on US customers, because the size of the impact varies hugely by product category and price point. Second, get your HTS codes sorted properly now rather than reactively — misclassified goods risk delays, extra charges, or shipments being held at the border, all of which land as customer complaints on your desk. Third, decide whether you absorb the new duty cost, pass it on transparently at checkout, or adjust pricing structurally; silently eating the cost without adjusting margins is the option most likely to hurt you three months from now when it shows up in your numbers. If you use a fulfilment platform or marketplace (Amazon, Etsy, Shopify), check now whether they’re handling broker filing and duty collection automatically or whether that responsibility sits with you — the answer differs by platform and by shipping method, and getting caught out here causes shipments to stall.

If US sales are a meaningful part of your business and this is starting to feel like it needs proper systems rather than manual handling, this is exactly the kind of operational complexity that’s worth automating rather than absorbing into someone’s weekly to-do list. BuildApps builds the kind of order-processing and compliance tooling that takes this off a person’s plate permanently rather than patching it manually shipment by shipment.

Don’t assume it’s someone else’s problem

Even SMEs who don’t sell directly to US consumers can be affected indirectly — if you import components or stock from suppliers who route through the US, or if a wholesale customer of yours re-exports there, the ripple effects of this change can show up in your supply chain costs even without a single US-bound parcel leaving your own premises. It’s worth a five-minute conversation with any supplier or customer with US exposure to check whether this affects your relationship with them.

The takeaway

If any part of your revenue depends on shipping to US customers, check your current process against the new Entry Type 13 requirements this week, get your HTS codes and broker arrangements confirmed, and decide deliberately how the added duty cost gets reflected in your pricing — before a customer complaint or a stalled shipment forces the decision for you.