Seems that we have a new euro printing facility in the euro area. But since the European Central Bank does (apparently) not update the list of printing works any more :-[ and the European Commission does not provide that info either, there has been some guessing in the past few days.
Yesterday somebody at eurobilltracker.com wanted to enter a new €10 note but could not do that, because of the "unknown" F code in the serial number. So far that "F" has been unassigned. Not any more though - it now means Oberthur Fiduciaire AD.
The first two parts of the company name sound familiar; Oberthur has been printing euro notes in France for many years. But AD? Well, these ones come from Bulgaria - the printing facility in Sofia is a joint venture of Oberthur (70%) and the Bulgarian central bank (30%). And the Bundesbank in Germany just had a couple million €10 notes made there, see the tender (https://ted.europa.eu/udl?uri=TED:NOTICE:413952-2018:TEXT:EN:HTML&src=0#id4-V.) here ("Section V: Award of contract").
So Oberthur in Sofia got a contract about making 424 million €10 notes. Date of conclusion was in August 2018. All fine, but I still wonder (and asked the EC) whether a current list of printers is considered classified info these days. After all, the ECB still says (https://www.ecb.europa.eu/euro/banknotes/design/html/index.en.html) (scroll down to Printing works and letters) that the F is unassigned ...
They have a permission to print euro notes since May 2017, but the only information about the letter F that I could find is a short note here (https://mriguide.com/european-monetary-union-new-prefix-letter/).