Only import of goods and not services is subject to VAT in Bulgaria. Art 11 (1 and 2)
The import of goods is not considered to be a "deal" (i.e. "transfer of rights over goods or performance of services" -art 2 VATA).
The VAT is levied, collected and transferred into the state budget by the customs authorities It is levied on all importers, regardless of their being "registered persons" or not.
No VAT is levied when (art 23, VATA)