The Canary Islands legally form part of Spain and islanders use the euro for all financial transactions. According to Lonely Planet, the island's retailers and merchants accept all cash payments in euros as well as credit and debit card transactions.
USA Today explains that the Canary Islands trace their relationship with Spain back to the 1400s and the arrival of the Castilian Conquest in 1402. This long relationship largely defines the economic practices of the islands, which mirror those of the mainland. Spain's adoption of the euro extends to all of its territories and overseas areas, including the Canary Islands and the Balearic Islands.