Unless they are patented (eg. Many fruit, vegetable, orchids etc), endangered (check CITES, vut taiwan also has its own protections for native species) or a controlled substance (should be obvious, but can check the controlled drugs list to confirm the more obscure things) you are fine to export at will. Its the importing country you need to be careful about. Phytosanitary inspections are only available in a few cities in the west. They can travel to any location to do remote inspections but will charge you and you better be shipping a container load to bother them hehe. Well, at least a lot. Your situation wont qualify.
Otherwise just show up at their office with CLEAN seeds and your ID with all the shipping details, weights, shipping box etc and youre good to go within an hour usually.
Note. You must ship the original certificate in the box with the seeds. Netherlands can be picky so I always add 3 photocopies each of the phytosanitary certificate, packing list and invoice.
New laws require VAT and all that annoying shit now too.