Do I need to add printed invoices to a shipment to the United Kingdom?

No, but for a shipment to the United Kingdom it is mandatory for both the European and UK customs to be able to present an invoice. DPD has agreed with customs that there is no need for a printed paper invoice, but that a digital invoice for each parcel is sufficient. All items in the parcel must be clearly described on the invoice. The digital invoice can automatically be generated from the data you provide for each parcel, so make sure your data is compliant. Attention: Customs UK can at all times request an original invoice. The customer service of DPD will request this from you, make sure you can always provide it within 24 hours.