martinamr

I believe it‘s too late for the 2016 tax return, I think the absolute latest you could submit something for 2016 was at the end of 2020.

Letters („Briefpost“) to destinations outside of Germany can only contain documents (since a few years now, possibly January 2019)   edit to add: >>Ab dem 1.1.2019 können nur Dokumente in Briefen ins Ausland versandt werden. source: https://www.deutschepost.de/de/b/briefe-ins-ausland.html   So books need to be sent as Päckchen/Paket, and as the UK is no longer in the EU you need to fill out a customs form.

If you‘re mailing things using Deutsche Post/ DHL you‘re not allowed to use those plastic bags (unless you pay for „Sperrgut“)   An exception, of course, is for returns, because then you‘re technically not the customer, the shop is, and they have other terms and conditions.   https://www.paketda.de/verschicken/tueten.html

There are no „buyer‘s“ or „seller‘s“ Maklers here   If a house is being sold via a Makler, then s/he‘s the Makler for that house   And s/he can easily answer all of these questions you have 😊