Uncle Mun Coffeeshop Knowledge Chief

Ran a small online biz through this. The core rule: GST registration is compulsory once your taxable turnover crosses the prescribed threshold (on a rolling 12-month basis, or if you reasonably expect to exceed it). Below that, it's voluntary. Key considerations: 1) compulsory, watch your rolling 12-month revenue, once it's heading past the threshold you must register within the required window or face penalties, 2) voluntary early registration, worth it only if you sell mostly to GST-registered businesses (they claim it back) or have big input GST to reclaim, otherwise you're just adding 9% that makes you pricier to consumers, 3) registering means you charge GST, file returns, and keep proper records, more admin. For a consumer-facing store, most people wait until they must. Track your trailing 12-month turnover monthly so you don't cross unknowingly. Please verify the current GST threshold, rate, and timelines on the IRAS website, these figures do change.