UpSheets connects to Xero using OAuth, which requires you to login to your Xero account and approve the connection. UpSheets does not see, or store your Xero login details and has no access to your Xero account after you have finished using it. After clicking connect - You can verify that you are indeed logging into Xero by looking at the address in your browser when you are redirected to login - it will be on the xero.com domain: https://malcolm-en-gb.s3.eu-west-1.amazonaws.com/instances/j0x2GOjMS3/resources/JRU9qS1Jee/secure.png (secure) All data transmitted between you, UpSheets and Xero is secured using industry standard HTTPS/TLS encryption.