Setting up Amazon two factor authentication in the UK

Brief version extracted from here - http://www.techworld.com/security/how-brits-can-enable-amazon-two-factor-authentication-security-now-3631955/

1. Sign into Amazon.com, rather than .co.uk
2. Go to "Your account > Change account settings"
3. In "Advanced security settings" confirm SMS authentication
4. Enter mobile number, type in the six-digit SMS code sent to that device.