Reverse charge in Poland regulations up to the end of 2012 stated that there was an obligatory reverse charge mechanism used on domestic supplies of goods, performed by supplier not established in Poland (even if supplier was registered for VAT purposes in Poland), when purchaser was a taxpayer established in Poland.
After amendments that came into force at the beginning of 2013 there is an obligatory settlement of VAT by the supplier not established in Poland, if the supplier is registered for VAT purposes in Poland (regardless whether purchaser is a taxpayer established in Poland or not).