When you signed up, you selected to use Google or Facebook to authenticate your access to TransferWise and did not create a separate TransferWise password.
To login, you simply need to select Google or Facebook and our site checks with your chosen provider using the OAuth protocol to verify your identity.
If you are signed on to either website from the same browser at the time, you are likely to get passed through – otherwise you would be asked to login with your relevant password on a separate screen. You cannot log directly in to TransferWise using your Google or Facebook e-mail and password combination, you need to click one of the above buttons and then login to their own site, which will then redirect you back to us.
From an authentication perspective, accessing TransferWise is in this case as secure as accessing your Google mailbox or Facebook page.
Please note: TransferWise will not post anything to Google+ or Facebook on your behalf without your authorisation. Also, if your name on either service does not match the name on your bank account, you will need to update this from your 'Settings' page after signing up, as this may lead to a delay in your first payment.