Depending on what you're sending and where, you may need to include:

• A commercial invoice
   (Even private sellers may be asked to include one. It describes the object and its value.)
• A customs declaration
   (CN22 or CN23 forms, depending on the object value and shipping company)
• A CMR document (for vehicles)
• Proof of payment or sale, if requested
• Your VAT number, if you’re a professional seller
• EORI number (required for most non-EU sellers shipping into the EU)

Missing or incorrect paperwork can lead to delays, returns, or additional customs fees.

Tip: If a return is needed, always share the MRN (Movement Reference Number, provided by customs) with the shipping company handling the return. This prevents customs from treating the return as a new import and charging VAT or duties twice.