A private shipment will only be accepted as such if the number of items is reasonable. Shipments to companies that have an EORI number are accepted as business shipments. This number is absolutely necessary in order to be able to declare a business shipment. You can use the following link to check the validity of your EORI number: https://ec.europa.eu/taxation_customs/dds2/eos/eori_validation.jsp?Lang=de
If you, as a private individual, only occasionally import consignments into the European Union, you do not need an EORI number and can have the consignment declared as a private individual. Customs usually considers 3 shipments / year to be occasional. If you have more imports as a private person, you also need an EORI number. As a company, you generally need an EORI number.