Payment account information service is a descriptive way of referring to an account information service (AIS), the regulated open banking service covered in full under that entry. The extra words simply spell out which accounts the service reads: payment accounts, as defined in European payments law.
Under the Second Payment Services Directive, an account information service is an online service that collects and consolidates information on one or more payment accounts a customer holds with one or more providers. The firm offering it, an account information service provider, must be registered or authorised, and it can only access data with the customer's explicit consent. The bank holding the account must give access through a secure interface, usually an open banking API, and the customer authenticates with the bank using strong customer authentication.
The narrower scope is important. Savings products, mortgages and investment accounts that cannot be used for day-to-day payments generally fall outside the PSD2 right of access, so a service reading them relies on voluntary agreements rather than the directive. The United Kingdom kept the same concept after Brexit through its own Payment Services Regulations 2017.