On 1^st April 2017 was the second year Goods and Services Tax (GST) in Malaysia was implemented. Though Royal Malaysian Customs Department (RMCD) has recorded good tax collection, the signs of non-compliance have increased. Using the Responsive Regulation Theory, this study investigates audit probability and tax knowledge determination on GST compliance among businesses in Malaysia. In order to do this, a survey was conducted from April 2016 until the end of August 2016 and the Respondents were business operators registered with RMCD, under the GST System. The results show that both audit probability and tax knowledge contribute significantly to the compliance level among businesses. These findings are important for tax regulators (RMCD specifically) in promoting tax knowledge through continuous programmes and workshops, as GST is still at an early stage of implementation.