A few European tax offices will require that your company documents and registration forms are "notarised and apostilled" before you can submit them to the authorities to apply for a VAT registration.
A notarised document is one carrying authenticated signature(s) of the person(s) authorised or required to sign it, and the signature of a notary public witnessing the signature(s), accompanied by an impression of his or her official notary seal. If a tax office requests it, the authorised signatory will need to visit a Notary Public (or have one come to your office) and sign the required documents in his/her presence. The notary will certify the documents after witnessing the signature.
The definition of an apostille is 'the authentication of a document for use in another country'. The apostille certificate confirms the signature, seal or stamp on a document to be genuine so that it will be accepted when presented in another country within the European Union. It is permanently glued to another document and then an embossing mechanism, often called the apostille seal or apostille stamp, is used to emboss the document with a government crest.
Usually the notary public you engage for the witnessing service will be able to arrange the apostille for your as well