"The EU Blue Card is a measure to attract and retain highly qualified third-country workers as part of an approach based on the needs of the Member States of the European Union."
The EU Blue Card offers mobility within the Member States of the European Union after 18 months of legal residence in the first Member State as an EU Blue Card holder. The EU Blue Card holder and his or her family members are allowed to move to another Member State for the purpose of highly qualified employment as meant in the EU Blue Card Directive. The Dutch highly skilled migrant permit is restricted to The Netherlands.
The EU Blue Card holder however is allowed to accumulate periods of residence in different Member States in order to fulfil the requirements of 5 years of legal and continuous stay. Provided, that the applicant has legal and continuous residence for two years immediately prior to the submission within the territory of the Member State, where the application for the EC-long term residence permit is lodged. Obviously this possibility is not open for Dutch highly skilled migrants.
Absence of the territory of the European Union by the EU Blue Card holder is not considered an interruption of the 5 years of legal and continuous stay, provided this period is shorter than 12 consecutive months and does not exceed in total 18 months. These periods of absence are restricted to cases where the EU Blue Card holder has returned to his country of origin to work as an employee, self-employed person, to perform voluntary service, or to study. Holders of the Dutch highly skilled migrant permit are not allowed to have any interruption in their 5 years legal and continuous stay to qualify for the EC-long term residence permit.
Once the EC-long term resident status is acquired by the former EU Blue Card holder, longer periods of absence are allowed than those provided for in the Directive about the EC-long term resident status for third country nationals. They are allowed to be absent of the territory of the European Union for 24 months. Former Highly skilled migrants, who also have acquired a EC-long term resident status, are only allowed to be absent from the territory for a maximum period of 12 months.