GST is a form of consumption tax imposed on the import of goods, as well as nearly all supplies of goods and services in Singapore. GST registration can either be a voluntary action or a compulsory requirement as provided by IRAS. In general, a business may register for GST voluntarily, if its turnover is less than $1 Million per annum. It is however compulsory for a business to register for GST when its turnover exceeds $1million per annum. Once you are registered, you are considered a GST collecting agent of the Singapore government.
Once you are GST registered, you must charge and collect GST at the prevailing rate (currently at 7%). This GST which you charge and collect (on behalf of IRAS) is known as output tax, and it has to be paid back to IRAS, normally on a quarterly basis. GST incurred on business purchases and other business-related expenses are known as input tax. Businesses on the other hand, can claim input tax if conditions for claiming are satisfied.
A GST-registered business is required to submit Form 5 GST return to IRAS (or to do e-filing via the IRAS Website) usually on a quarterly basis. The business will indicate its Total output tax and Total input tax for that in the GST return. The difference between output tax and input tax is the net GST payable to or refundable from IRAS. For the first GST filing, a business may also be allowed to claim pre-registration Input Tax, if it satisfies a few criteria defined by IRAS.
Once your company is registered for GST, it is compulsory to submit your GST returns (via e-filing method) on a quarterly basis. Failure to e-File is a severe offence punishable with a fine or/and imprisonment terms. Even if your company has no transaction performed, a “NIL” GST return must still be submitted within one month from the end of every 3 Calendar Months.