How to get a PayPal API Username, Password and Signature information?

You can access PayPal via API only if you have a PayPal Premier / Business / Website Payments Pro account

  1. Log in to your PayPal Premier or Business account
  2. Click the Profile subtab located in the top navigation area
  3. Click the API Access link under the Account Information header
  4. Click the Get Started link under the Request API Credentials heading
  5. Click the My selling preferences sub option in left sidebar
  6. Click the Update option for API access item
  7. Complete the API Credential Request form by clicking the agreement checkbox and clicking Submit
  8. You will now get the API username, password and signature
  9. Copy the values from this page into the PayPal Account Data form in 1ClickBusiness Payments settings

If you set API details earlier, click on View API Signature