GST registration & filing — handled completely by Karman
Whether you're approaching the S$1M threshold or want to register voluntarily to claim input tax, Karman manages your GST registration, quarterly F5 returns, and IRAS correspondence from end to end — so you never miss a deadline or overpay.
Complete GST compliance — registration to quarterly returns
Karman handles every step of the GST process so you stay compliant and maximise your input tax claims.
Eligibility Assessment
We review your taxable turnover and business model to determine whether you must register compulsorily, should consider voluntary registration, or are not yet required to register — and explain the implications of each option.
myTax Portal Registration
We prepare and submit your GST registration application to IRAS via myTax Portal. We handle all forms, supporting documents, and IRAS queries on your behalf so you receive your GST number as quickly as possible.
Quarterly GST Returns (Form F5)
Every quarter we prepare your Form F5, reconcile output tax and input tax, and submit on time. You review and approve before we file. No missed deadlines, no manual uploads.
Input Tax Claims Optimisation
We identify and claim all eligible input tax on your business purchases and expenses, maximising the refunds or offsets due to your company. Partial exemption calculations handled where applicable.
GST Audit Support
If IRAS selects your company for a GST audit, we prepare all required schedules and documentation and liaise with IRAS directly on your behalf — protecting you from unnecessary assessments.
IRAS Correspondence Management
All letters, queries, and notices from IRAS relating to your GST account are handled by Karman. We respond accurately and on time, and keep you informed of anything requiring your attention.
Voluntary Registration Advice
We analyse whether voluntary registration makes commercial sense for your specific business — weighing the input tax benefits against the administrative obligations — before you commit to the mandatory 2-year minimum.
Reverse Charge & Overseas Services
If your business imports digital services or purchases from overseas suppliers, reverse charge rules may apply. We ensure your GST accounting correctly reflects these obligations under IRAS guidelines.
Registered and filing in 3 steps
We take care of everything — from the registration decision to your first quarterly return.
We assess whether you must or should register
We review your financials, revenue projections, and supply type to determine whether GST registration is compulsory, beneficial, or premature for your business — and walk you through the implications of each path.
We submit registration to IRAS via myTax Portal
Once you decide to proceed, we prepare and submit the GST registration application with all supporting documents. We handle any IRAS queries and confirm your GST effective date and registration number.
We manage quarterly F5 returns and input tax claims
Every quarter we reconcile your output tax and input tax, prepare Form F5, and submit on time. We flag opportunities to maximise your input claims and alert you to any issues before they become problems.
Tailored to your business
GST engagement fees depend on your transaction volume, filing complexity, and whether you need registration only or ongoing quarterly management. We quote transparently with no hidden add-ons.
Get a GST quote in 24 hours
Tell us your annual revenue, the nature of your supplies, and whether you need registration, ongoing filing, or both. We'll respond with a clear, fixed-fee proposal — no obligation, no ambiguity.
Get a quote Email us directlyCommon questions about GST in Singapore
You are legally required to register for GST when your taxable turnover exceeds S$1 million in the past 12 months (retrospective basis), or when you have reasonable grounds to expect it will exceed S$1 million in the next 12 months (prospective basis). You must apply to register within 30 days of becoming liable. It is important to monitor your rolling 12-month turnover regularly — businesses often miss the threshold and only discover it during an IRAS audit, by which point significant back-taxes and penalties may already apply.
Voluntary GST registration allows businesses with taxable turnover below S$1 million to register for and charge GST — and in return, claim input tax on their own business expenses. This is particularly valuable for B2B businesses whose clients are themselves GST-registered: those clients can claim back the GST they pay you, making the charge cost-neutral. However, voluntary registration comes with obligations — you must remain registered for at least 2 years and file quarterly returns. Karman helps you evaluate the financial case before you commit.
The GST rate in Singapore is 9%, effective from 1 January 2024. It increased from 8% to 9% on that date as the second step of the government's planned GST rate increase (from 7% in two stages). All GST-registered businesses must charge 9% GST on standard-rated supplies of goods and services in Singapore. Certain supplies — such as exports and international services — are zero-rated at 0%. Financial services, residential property rentals, and some other categories are exempt from GST.
GST-registered businesses must file a GST return (Form F5) within 1 month after the end of each quarterly accounting period. The standard quarterly periods end in March, June, September, and December, making the four filing due dates January, April, July, and October respectively. Late filing attracts a penalty of 5% of the tax payable, with further penalties applied if the return remains outstanding. IRAS can also take legal action for persistent non-filing. Karman prepares and submits your returns ahead of each deadline.
Late GST registration carries serious financial consequences. IRAS can impose financial penalties and — critically — will back-charge GST on all taxable sales made from the date you should have registered, regardless of whether you collected it from your customers. You cannot retroactively add GST to past invoices and recover it from customers. This means the full back-tax liability comes out of your own pocket. The earlier you identify and address a potential registration obligation, the better your position. Karman can review your exposure and advise on the best course of action, including voluntary disclosure to IRAS.
Other services your business may need
Don't let GST catch you off guard
Whether you're approaching the threshold or ready to register voluntarily, Karman handles GST from registration through every quarterly return. Get in touch for a clear, fixed-fee quote.
Get a quote today