CN23 Troubleshooting Support

This guide explains the most common reasons parcels are delayed, returned, or rejected due to incorrect or incomplete CN23 customs declarations, and how to avoid them.

When a CN23 Is Required

A CN23 is required when:

• Goods value is over £270, or
• The service mandates CN23 (many tracked / Parcelforce services), or
• An electronic customs declaration is required

CN23 is always used for parcels, not letters.

Common Reasons Items Are Returned

Most Common CN23 Failure Points:

• ❌ Vague or generic descriptions
• ❌ Missing itemised breakdown
• ❌ Zero or unrealistic values
• ❌ Missing HS / commodity codes
• ❌ Missing country of origin per item
• ❌ Incorrect Incoterms / delivery terms
• ❌ Missing VAT / EORI where required
• ❌ Weight/value mismatch
• ❌ No commercial invoice attached
• ❌ CN23 not signed or not attached externally

Detailed Troubleshooting & How to Fix

1. Description Too Vague

CN23 requires item-level detail, not a single summary.

❌ Unacceptable:

• “Goods”
• “Merchandise”
• “Parts”
• “Samples”
• “Accessories”

✅ Required:

• What the item is
• What it’s made of (where relevant)
• What it’s used for

Descriptions must allow customs to classify the goods without guessing.

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2. No Itemised Breakdown

Each different item must be listed separately on the CN23.

❌ Incorrect:

• One line covering multiple products

✅ Correct:

• Separate lines for each product type, quantity, and value

Totals must equal the declared parcel value.

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3. Missing or Incorrect HS (Commodity) Codes

HS codes are mandatory on CN23.

Requirements:

• Minimum 6-digit HS code
• Code must match the item description

❌ Common issues:

• Leaving HS codes blank
• Using a generic or incorrect code

Incorrect HS codes lead to mis-classification and delays.

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4. Country of Origin Missing or Incorrect

Country of origin means where the goods were manufactured, not where they are shipped from.

❌ Incorrect:

• Leaving blank
• Listing the export country instead of manufacture

Each item must have its own country of origin.

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5. Commercial Invoice Missing or Incomplete

A CN23 must be accompanied by a commercial invoice.

The invoice must include:

• Seller and buyer details
• Item descriptions
• HS codes
• Quantities and values
• Currency
• Country of origin
• Delivery terms
• Signature and date

❌ CN23 alone is often insufficient.

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6. Weight or Value Mismatch

Declared data must match:

• CN23
• Shipping label
• Commercial invoice

❌ Mismatches trigger automatic customs holds.

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7. Missing VAT, EORI, or Importer Information

Required when sending:

• Commercial goods
• Business-to-business shipments
• Goods to the EU or other regulated destinations

Common issues:

• Missing EORI number
• VAT number not supplied when required
• Recipient details incomplete or inconsistent

Missing importer data can prevent customs clearance.

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8. Incorrect Delivery Terms (Incoterms)

Delivery terms determine who pays duties and taxes.

Common terms:

• DAP (Delivered At Place) – recipient pays charges
• DDP (Delivered Duty Paid) – sender pays charges

❌ Missing or incorrect terms may cause clearance delays or refusal.

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9. CN23 Not Signed or Incorrectly Attached

Requirements:

• CN23 must be signed and dated
• Must be placed in a documents pouch
• Must be attached to the outside of the parcel

❌ Forms placed inside the parcel may not be seen by customs.

CN23 Troubleshooting Support – Frequently Asked Questions