All available subscription plans can be checked on the Plans & Pricing page. You can play around with the check frequency and subscription period to find the most suitable option for you or contact Support, if any questions arise.
There are more than 45 payment methods depending on the country, including Visa, Mastercard, American Express, PayPal, Direct Debit, Discover/Novus, Eurocard, Wire Transfer, UnionPay and many more.
How to find
The Billing page can be accessed via the drop-down menu in the top right-hand corner of the account. 
Under Billing, you can find your invoices, information about your subscription plan limits, transaction and payment history.
The Billing page shows complete details about your subscription plan and available usage limits. The Current Plan tab shows complete details about your subscription plan and available usage limits. Here you can also upgrade, downgrade or renew your subscription and top-up your SE Ranking balance.
Under Invoices, you can view complete details about your subscription purchases, renewals, upgrades, and downgrades. Here you can also download any of your invoices for any time period.
The Balance transactions tab displays the complete detailed history of your internal transactions (additional payments made from your internal SE Ranking balance). Such as User seats purchases, Keyword grouper charges, etc.