GST Registration Singapore - Register & File Returns with IRAS
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.
Compulsory vs voluntary GST registration
Most businesses register only when required by law. But for B2B businesses with GST-registered customers, voluntary registration can be a meaningful tax saving.
| Aspect | Compulsory registration | Voluntary registration |
|---|---|---|
| Trigger | Taxable revenue exceeds S$1M in past 12 months (retrospective) or expected to (prospective) | Below S$1M revenue but business chooses to register |
| Application deadline | Within 30 days of becoming liable | Any time |
| Minimum registration period | None (until you fall below threshold) | 2 years minimum once registered |
| GIRO requirement | Optional (but recommended) | Mandatory - must set up GIRO with IRAS |
| Filing obligation | Quarterly Form F5 returns | Quarterly Form F5 returns |
| Best for | Businesses naturally over the S$1M threshold | B2B businesses with mostly GST-registered customers, importers reclaiming input tax |
| Risk if late / wrong | Back-tax + penalty (you owe GST you didn't charge) | None - you control the timing |
Not sure which applies? Try our GST Eligibility Checker →
Standard-rated, zero-rated, exempt & out-of-scope supplies
Not every sale you make is taxable at 9%. The supply category determines how it's recorded on your F5 return - and whether you can claim related input tax.
| Supply category | GST rate | Examples | Input tax claimable? |
|---|---|---|---|
| Standard-rated | 9% | Most goods & services sold in Singapore: retail, software-as-a-service, professional services | Yes |
| Zero-rated | 0% | Exports of goods, international services, certain bunker fuel and ship/aircraft supplies | Yes |
| Exempt | Not applicable | Financial services (interest, FX), residential property sale & rental, sale of investment-grade gold | No (or partially, with apportionment) |
| Out-of-scope | Not applicable | Sales made overseas without entering Singapore, third-country sales, transfers of ongoing concerns | Generally no |
Why the categories matter
Mis-classifying a supply is the most common GST audit issue we see. Treating a zero-rated export as standard-rated overstates your GST liability and frustrates your customer. Treating an exempt supply (e.g., interest income) as standard-rated may force you into a partial-exemption calculation that limits how much input tax you can recover. Karman maps each revenue stream and recurring expense to the right category at registration, then maintains the classification in your accounting system.
Blocked input tax - what you can't claim
IRAS specifically blocks input tax on certain expenses regardless of business purpose: club subscriptions, motor cars (other than commercial vehicles), employee benefits where there's no nexus to your taxable supplies, and medical / family-related insurance. Misclaiming these creates a GST audit trail. We mark blocked input tax automatically in your books to avoid accidental claims.
Reverse charge, OVR & low-value goods regimes
Singapore has progressively brought imported services and digital goods into the GST net. Whether you're an importer or an overseas supplier selling into Singapore, these rules can apply.
Reverse Charge (B2B imported services)
Singapore GST-registered businesses must self-account for GST on imported B2B services (e.g., overseas SaaS, cloud hosting, professional advice) where they cannot claim full input tax. The same business records both output and input GST in the same F5 return.
Applies if: You make exempt supplies or are not entitled to full input tax recovery, and your imports of services exceed S$1M per year.
Overseas Vendor Registration (OVR)
Overseas suppliers selling digital services or low-value goods directly to Singapore consumers must register for GST under the OVR regime once their global turnover exceeds S$1M and Singapore B2C sales exceed S$100K. Common OVR-registered companies include Netflix, Spotify, Shopify, and many SaaS providers.
Applies if: You are a foreign company selling B2C digital services or low-value goods (≤ S$400) to Singapore consumers above the thresholds.
Low-Value Goods (LVG) regime
From 1 Jan 2023, GST applies to low-value goods (≤ S$400) imported into Singapore by air or post and sold to consumers. Overseas e-commerce sellers and operators of electronic marketplaces (Amazon, Shopee, Lazada) collect and remit GST under LVG rules.
Applies if: You sell low-value goods cross-border to Singapore consumers above the S$1M global / S$100K SG B2C thresholds.
Major Exporter Scheme (MES) & IGDS
Companies with significant exports can apply for the Major Exporter Scheme (MES) to import goods without paying upfront GST. The Import GST Deferment Scheme (IGDS) lets approved importers defer import GST to the F5 return. Both schemes dramatically improve cash flow for trading and manufacturing businesses.
Applies if: Zero-rated supplies are 50%+ of total supplies (MES) or you import substantial goods regularly (IGDS).
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.
Common GST mistakes — and how we avoid them
After running thousands of F5 returns, the same handful of errors keep producing IRAS queries, audit risk, and avoidable cash-tax pain.
Missing the S$1M threshold
Trailing 12-month revenue creeps over S$1M and the trigger is missed. Once spotted by IRAS, you owe back-GST on past sales - payable from your own pocket since you can't retroactively bill customers. We monitor your rolling revenue and flag the threshold early.
Mis-classifying zero-rated exports
Treating an export of goods or international service as standard-rated overstates your output GST and frustrates the customer. Conversely, claiming zero-rating without supporting documentation (export bill of lading, customer's overseas address) draws audit scrutiny.
Claiming blocked input tax
Claiming GST on motor cars (non-commercial), club subscriptions, or non-business medical insurance is blocked under IRAS rules. These claims look small but appear on every audit. We tag blocked categories at the chart-of-accounts level so they're never claimed.
Ignoring reverse charge on imported services
Buying overseas SaaS, cloud, or consulting and not self-accounting for reverse-charge GST is a common omission for partially-exempt businesses. The exposure compounds quietly over years until an audit discovers it.
No partial-exemption calculation when needed
Mixed-supply businesses (some standard-rated, some exempt) must apportion input tax under IRAS's de minimis or standard formula. Failing to do this - or doing it wrong - can lead to back-tax assessments going back several years.
Late F5 returns
Each F5 return is due within 1 month of the quarter end. Late filing automatically triggers a 5% penalty on tax payable, plus daily interest. Persistent late filing escalates to IRAS legal action. We file every return ahead of the deadline.
Common 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.
Deregistration is allowed if your taxable revenue falls and is expected to remain below S$1M for the next 12 months, or if you cease trading. You apply via myTax Portal, settle final GST liabilities, and account for GST on remaining business assets above S$10K (deemed supply on cessation). Voluntary registrants must complete the 2-year minimum before deregistering. Karman manages the closing F5 return, deemed-supply calculations, and the formal application.
IRAS typically processes GST registration applications within 10 working days for straightforward cases. Voluntary registrations and applications from new companies may take longer (2–4 weeks) as IRAS may request supporting documents (revenue projections, bank statements, contracts) and require GIRO setup. We prepare a complete first-time application to minimise back-and-forth and shorten the approval timeline.
You must keep tax invoices issued and received, credit notes, debit notes, customer accounting records (for partial exemption), bank statements, and all source documents supporting F5 entries - for at least 5 years from the end of the relevant accounting period. Tax invoices over S$1,000 must include the customer's name and address. IRAS can request these during an audit, and missing documentation can disqualify input tax claims and trigger penalties.
GIRO (General Interbank Recurring Order) is an automatic bank-deduction arrangement with IRAS for paying tax. For voluntary GST registrants, GIRO is mandatory. Compulsory registrants are strongly encouraged to set up GIRO to avoid late-payment penalties - it auto-debits any net GST payable on filing day. GIRO setup takes about 3 weeks once the form is signed and lodged with your bank. Karman handles the GIRO setup as part of the registration process.
Yes, partially. You can claim pre-registration input tax on goods still held at the date of registration (acquired up to 6 months before) and on services received up to 6 months before registration, provided the goods or services are used for taxable supplies post-registration. You'll need to support claims with original tax invoices and inventory records. We compile and review pre-registration claims as part of your first F5 return.
If your business makes both taxable and exempt supplies (e.g., a financial services firm that also sells consulting), you can only claim input tax that relates to taxable supplies. The "de minimis" rule allows full input recovery if exempt supplies are below S$40K per quarter and 5% of total supplies. Above the de minimis, you apportion input tax using IRAS's standard formula. Karman performs the partial-exemption calculation each quarter for mixed-supply clients.
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