A paying manager is a manager account that controls monthly invoicing billing setups used by the Ads accounts beneath it in a manager account hierarchy.
Users with standard and admin access that are signed in to the paying manager (or any manager account above it) can view invoices, edit budgets and perform billing transfers for Ads accounts under that manager. Although one Ads account can be linked to multiple manager accounts, the billing setup for that Google Ads account is managed by only one of those manager accounts. That’s because a single Google Ads account can only have one active billing setup at any given time.
You can find the paying manager name and ID for your Google Ads accounts by navigating to the “Billing settings” page.