In the past, to each of the above identification numbers corresponded a separate identification document. However, in 2006, the single Citizen Card was implemented. This card includes the civil identification, the tax identification, the Social Security and the Healthcare user numbers, replacing the old corresponding identification cards. Besides this, the Citizen Card also replaced the previous Voter's Card, although not including the voter's number. The replacing of the previous separate identification documents by the single Citizen Card is a gradual process, only being mandatory for a citizen, when one of his/her old documents expires. The driver's license continues to be an entirely separate document.