The seats are allocated on the basis of the election results and in accordance with the following rules:
The election of the 208 senators who are elected by universal suffrage that is free, equal, direct and secret, is carried out as follows:
The electorate can vote for a maximum of:
3 candidates in the peninsular constituencies. 2 in Gran Canaria, Mallorca, Tenerife, Ceuta and Melilla. 1 in the remaining island constituencies.
Subsequently, those who obtain the highest number of votes are proclaimed elected until the total number of senators in each constituency is reached.
The ballot paper is brown, unique for each constituency, and the same for all candidates.
Nominations are ordered on the ballot paper according to the results obtained in the previous elections, and the candidates, within each candidacy, in the order freely established by the candidacy itself. The voter may place a cross in the box next to the candidate of his or her choice, irrespective of his or her place in the nomination.
Voters can cast their vote:
For a maximum of 3 candidates in the provincial constituencies. For a maximum of 2 in Gran Canaria, Mallorca, Tenerife, Ceuta and Melilla. For a maximum of 1 in the remaining island constituencies.
The candidates chosen by the electorate do not necessarily have to belong to the same party.
The ballot paper, depending on the number of candidates presented in each constituency, may have different sizes and the candidates may be listed on both sides of the ballot paper (front and back)
Votes may be valid or null.
The following are regarded as valid votes:
cast in the ballot box in accordance with the legal requirements.
An abstention is:
Votes cast in envelopes that are different from the official model or are altered; or ballot papers that are different from the official model, altered, ripped or torn; as well as those cast in ballot papers without envelopes; and those in which the will of the voter cannot be ascertained (for example, envelopes containing more than one ballot paper from different candidates) are invalid.
In the event that the ballot envelope contains more than one ballot paper of the same candidature, it shall be counted as one valid vote.
In the case of elections to the Congress of Deputies, the following shall also be null: votes cast on ballot papers on which the names of candidates have been modified, added or crossed out, or their order of placement has been altered, as well as those on which any other type of alteration has been made (such as, for example, to the symbol of the candidacy).
In the case of Senate elections, votes cast on ballot papers with more than three names in the provincial constituencies, more than two in the island constituencies of Gran Canaria, Mallorca and Tenerife and in the towns of Ceuta and Melilla, and more than one in the rest of the island constituencies, shall also be null votes.
Votes cast on ballot papers containing a sign, cross or mark next to one of the candidates shall be considered valid, provided that they are not so important or significant as to be considered to have altered the configuration of the ballot paper or to have expressed disapproval of one of the candidates or of the political grouping to which they belong.