If you want to open an ISA, you’ll need to be a UK resident or a crown servant (for example a diplomat, their spouse or civil partner). Other than that, it’s up to each account provider to set their own rules. There might be age restrictions, so you may have to be 16 or 18 for some types of account, and some banks may reserve their best-paying savings accounts for customers who have a current account with them. Some small building societies may restrict their accounts to people who live in their area. For example, the Ipswich Building Society only offers its savings accounts to existing members or people who live in its local postcode areas. Make sure you check the eligibility rules for any account you’re considering.