What Customs Form Do I Need to Send a Parcel from the UK to the USA?

The Short Answer

For UK → USA shipping in 2026, the customs form you need depends on the carrier and the parcel value:

• Royal Mail under 2kg and £270: CN22 (green sticker)
• Royal Mail over 2kg or £270: CN23 (larger declaration)
• UPS, DHL, FedEx (any value): Commercial invoice with HS codes
• Platforms like TradeWind: Auto-generate the right form

Since the US ended de minimis in February 2026, every commercial parcel attracts US import duty — accurate paperwork matters more than ever. Wrong HS codes or vague descriptions trigger holds and delays.

CN22 vs CN23: The Royal Mail Forms

The CN22 and CN23 are Universal Postal Union forms used by Royal Mail (and other postal operators worldwide). They’re the customs declarations attached to postal parcels.

CN22 — the green sticker

| Use when | Royal Mail parcel up to 2kg AND up to £270 value | | Size | 9 cm × 14 cm sticker (green border) | | Format | Adhesive label affixed to the parcel | | Languages | English and recipient country language acceptable |

Fields on the CN22:

• Sender name and address (return address)
• Recipient name and address
• Contents tick boxes (Gift, Documents, Commercial Sample, Returned Goods, Other)
• Description of contents (specific — “leather wallet, brown, 1 piece” not “gift”)
• Quantity
• Value in £ (some versions accept multiple currencies)
• Weight in grams
• HS tariff code (required for commercial items)
• Country of origin (UK, England, Scotland, etc.)
• Sender signature and date

CN23 — the longer declaration

| Use when | Royal Mail parcel over 2kg OR over £270 value | | Size | A5 sheet (one side or both sides) | | Format | Adhesive pouch on the parcel, often a clear plastic CP72 wallet |

CN23 fields are an expanded version of CN22, including:

• More detailed contents breakdown (multiple line items)
• More space for HS codes and descriptions
• Mode of transport
• Insurance details
• Invoice reference
• Importer/exporter reference numbers
• Detailed reason for export

For Royal Mail Marketplace PDDP shipments, the CN23 is the standard form because most parcels exceed CN22’s value threshold once duty pre-payment is factored in.

Commercial Invoice — the Courier Form

UPS, DHL, FedEx, and other commercial couriers don’t use CN22/CN23. Instead, they require a commercial invoice — a more detailed document.

What goes on a commercial invoice:

• Exporter (your business) name, address, EORI, VAT number
• Importer (US recipient) name, address, contact
• Invoice number and date
• Reason for export (Sale, Gift, Sample, Return, Repair)
• Itemised contents:
  • Line item description (specific)
  • HS tariff code (10 digits where possible — US uses 10-digit HTS codes)
  • Country of origin per line item
  • Quantity
  • Unit value
  • Line total
• Total declared value in GBP and USD
• Currency
• Incoterms (DDP, DAP, EXW — for UPS WWE DDP, this is “DDP”)
• Shipping cost and insurance breakdown
• Signature and printed name

The commercial invoice is typically printed in triplicate:

• One inside the parcel
• One in a clear pouch on the outside
• One filed by the sender

Why the commercial invoice matters more than CN22 / CN23

US Customs and Border Protection looks at the commercial invoice for:

• HS code accuracy — wrong code triggers duty audit
• Declared value vs HTS database — outlier values trigger inspection
• Country of origin — for trade preference and tariff classification
• DDP marking — confirms duty pre-payment

The CN22 / CN23 forms include similar information but in a much shorter, less detailed format suitable for postal traffic. For courier traffic, the commercial invoice is the real document.

What Each Form Looks Like in 2026

Here’s a side-by-side summary:

What to Declare for Common UK→USA Shipments

The most common reason for customs holds is vague or wrong content descriptions. Here are good and bad examples:

Rules of thumb:

• Specific noun + key attributes + retail packaging note
• Always include HS code (preferably 6-digit minimum, 10-digit for US)
• Avoid “gift”, “merchandise”, “sample” as primary description (use the item name)
• Match what’s on the commercial invoice to what’s inside

Gift vs Commercial: Does It Matter?

Yes, but less than it used to. Since the US de minimis ended in February 2026:

• Gifts under $100 sent person-to-person: still attract duty in 2026, but often at simplified rates
• Commercial shipments: always attract duty
• Marking “Gift” on the form is fine for legitimate personal gifts but doesn’t avoid duty
• Fake “gift” labels on commercial shipments: customs fraud, parcels destroyed

The honest declaration approach always wins long-term — see the USA shipping after de minimis guide.

HS Codes — The Critical Field

The HS (Harmonised System) tariff code determines the duty rate. The US uses 10-digit HTS codes; the international standard is 6-digit HS codes.

For UK senders:

• 6-digit minimum acceptable on most paperwork
• 10-digit US HTS preferred for couriers and DDP shipments
• Wrong codes trigger duty audits, parcel holds, and additional fees

TradeWind maintains your product HS codes in a catalog — once set, every shipment of that product uses the same code automatically. For guidance on finding the right code, see HS codes 101 and how to find your HS code.

How TradeWind Generates the Paperwork

Through TradeWind, the right customs form is generated automatically:

1. You book a parcel with weight, value, and contents pulled from your catalog
2. TradeWind picks the carrier (or you select)
3. Form generated:
   • Royal Mail PDDP under 2kg and £270 → CN22 sticker
   • Royal Mail PDDP over those limits → CN23
   • UPS Worldwide Economy DDP → Commercial invoice in triplicate
4. HS codes auto-populate from your product catalog
5. Duty pre-calculated based on HS code, value, and destination state
6. Forms print alongside the shipping label

For commercial shipments, TradeWind’s B2B platform handles multi-piece consignments with a single master invoice — much faster than booking individual labels.

Practical Steps for Customs Paperwork

1. Set up HS codes per product in your catalog (use TradeWind or similar)
2. Use specific, accurate descriptions — not “gift” or “merchandise”
3. Always declare honest value — invoice should match what was paid
4. For couriers, ensure DDP is marked if pre-paying duty
5. Print paperwork in triplicate for couriers (inside, outside, file)
6. Match invoice to physical contents — discrepancies trigger inspection

The Bottom Line

For UK → USA in 2026:

• Small Royal Mail parcels: CN22 green sticker
• Bigger Royal Mail parcels: CN23 declaration
• All courier shipments: Commercial invoice with HS codes

The biggest customs-clearance wins come from accurate HS codes, specific item descriptions, and honest declared values. Platforms like TradeWind generate the right form automatically, but the upfront work of setting up clean product data is what pays off shipment after shipment.

For the broader USA shipping picture, see the full UK→USA guide. For HS codes specifically, see HS codes 101.

Sources

• Universal Postal Union — Customs Forms
• US Customs and Border Protection — Importing