If a Member State wants to change/update/replace the Paying Agency, it is mandatory to inform the Commission officially about it (art 102 of 1306/2013).
An Official letter to the Commission should be the basis for any changes. Once this letter is received and processed, the new PA name will be available for selection in the next Declaration of Expenditure created in SFC.
Still in SFC, the new PA name will be available for the creation of new Annual Accounts and new Control Data.