Although GST is collected on all purchases of goods and services in Singapore, you may as a visitor to Singapore claim for refund of the GST paid on your purchases if:
You are not a Singaporean or permanent resident of Singapore;

You have not at any time during the past 6 months exercised any employment in Singapore;

You have not spent more than 365 days in Singapore in the past 2 years;

You spent S$300 or more on goods at shops displaying the Tax Refund and Tax Free Shopping logos;

You take the goods out of Singapore through Changi or Seletar Airport within 2 months of purchase.