Social security has approved a new regulation to increase the self-employed (autonomo) payments for 2020 from 2 to 5 euros per month, depending on your previous payment.
The increase is retrospective from January 2020, and it has been put into force in November 2020.
November 2020 autonomo charge should have been already for the higher monthly amount, increased by 2€ to 5€ extra (which corresponds to the difference that should have been charged in October 2020).
As this increase is for the whole of 2020, they still need to charge retrospectively the increase for the first nine months (January to September 2020).
Because of this, Social security will charge the 2€ to 5€ extra, on a monthly basis, for the next nine months.
In summary: there will be 2€ to 5€ extra charges between December 2020 and August 2021, which will be independent to the standard monthly charges.
The increase will be direct debited on the last working day of each of those months.