In AdWords you’ll find the "Billing & payments" section under the settings wheel at the top-right corner in your account. In AdWords Beta select the tool icon at the top-right corner as shown below. Choose "Billing & payments" to start with the configuration that includes your country, billing address and payment details. Depending on the country you’ll see different options for payment methods and billing options. You can read more about them here. After entering all required information (country, tax information and billing information), you’ll have to read the Terms & Conditions for payments in Google AdWords. When you’ve accepted them and submitted your information to Google, your AdWords setup will be completed.