Offical sites
Republic of Slovenia Government Portal
Slovenia Business Point
Import to Slovenia
https://www.fu.gov.si/en/customs/areas_of_work/import_of_goods/#c3223
EU Custom and Tax
https://ec.europa.eu/taxation_customs/business/customs-procedures_en
Sloveia Custom
https://www.fu.gov.si/en/customs/work_with_us/e_customs/
EU Custom declaration
What is the identification procedure for VAT purposes for a foreign company that is not established but which carries out business activities in Slovenia?
Even if a company's head office is in another state and the company carries out activities in Slovenia only occasionally, it must be identified for VAT purposes.
It must obtain a Slovenian tax identification number and submit accounts for the tax period to calculate tax due. A foreign taxable person who obtains a tax identification number and VAT identification number in Slovenia is obliged to submit monthly VAT returns.
Obtaining a Slovenian tax number for a foreign business
http://eugo.gov.si/en/running/taxes/value-added-tax-vat/
No Tax Representative in Slovenia, but Tax Agent
https://www.asd-int.com/en/tax-representation-slovenia/
VAT in Slovenia
Foreign companies may register in Slovenia for VAT without the need to form a local company; this is known as non-resident VAT trading. There is no VAT threshold in Slovenia for the registration of non-resident traders; a VAT number must be in place before the commencement of taxable supplies.
https://www.tmf-group.com/en/services/companies/accounting-tax/vat/country-profile/slovenia/
Slovenia State Tax Portal -- Submit for VAT registration
https://edavki.durs.si/EdavkiPortal/OpenPortal/CommonPages/Opdynp/PageA.aspx
Invest Slovenia
https://www.investslovenia.org/
Consulent Fiscal Representative
Logistics and Warehouse service providers
http://www.tls.si/en/warehousing.php
https://gls-group.eu/SI/en/gls-slovenia