EV is Extended Validation. These are the certificates that give a green bar, with the company name.
The validation is almost the same as that of a OV-certificate, but there are a number of extra steps.
In addition to the aforementioned inspection at the Chamber of Commerce, before the certificate can be issued, a telephone check is also carried out with the person who applied for the certificate.
It is also possible that before that a check is done with the HR-department of your company, whether the applicant is authorized to sign or decide.
Therefore the application for an EV certificate can take a few days.