Thanks for the update @cbrace .
Worth noting that privater couriers work very differently than regular post and always have been know - for decades - to find creative ways to overcharge people with all kind of extra fees.
For a while i've been able to ship tea through DHL from India to my family's ( Germany ), then have it re-shipped to me with zero charges. Apparently this option was "terminated" all of a sudden.
Now that somebody mentioned Ebay and the chance they'll be in control of handling everything ... this is really bad news considering their past ( the infamous "GlobalShippingProgram" scam they've been running - maybe still at it... although less people biting - for years) .
Some marketplaces that didn't offer any way to process card payments already are implementing radical changes like switching to paypal-payments only since this is the only way they have to handle dual payments including future taxes automatically applied to invoices.
With Brexit taking effect on january already - looking like it'll be a hard one in the end - this will probably work as a preview of what's coming later as i'm reading essentially the same questions & doubts on international seller's forums .
New EU VAT regulations
I'm just googling it and can not find any website where to register and obtain the IOSS identification number. There is no any info on internet leading to some particular website of any country where can register.