[SUMMARIES]
The Golden Rule: You can only deduct expenses incurred “wholly and exclusively” for business trade (e.g., rent, staff salaries, marketing).
Strict “No-Gos”: Personal expenses and private car costs (S-plated) are never deductible, even if used for business meetings.
Key Limits: Special caps apply to renovations ($300k over 3 years) and employee medical expenses (max 1% of total payroll).
Audit Safety: You must keep all invoices and receipts (digital accepted) for at least 5 years to satisfy IRAS requirements.
[/SUMMARIES]
Discover how Singapore businesses can legally reduce taxable income by claiming allowable business expenses under IRAS. This comprehensive guide explains the critical differences between deductible and non-deductible costs, capital vs. revenue expenses, and special cases like R&D and renovations. Learn about medical expense caps and practical tips to stay compliant while optimizing your tax savings.
What Are Allowable Business Expenses Under IRAS?
In Singapore, allowable business expenses are the costs your business needs to pay in order to earn income, and IRAS lets you deduct them from your taxable income. Simply put, these are the everyday costs that keep your business running.
To qualify:
- The expense must be directly for your business, not for personal use.
- It should be necessary to generate business income, like rent for your office or materials for your products.
- Keep proper receipts and records – IRAS may ask to see them, and you need to keep them for at least five years.
Typical examples include:
- Rent and utilities for your office or shop
- Salaries and wages for employees
- Professional fees like accountants or consultants
- Marketing and advertising to promote your business
- Repairs and maintenance for equipment and premises
By understanding and claiming these expenses correctly, your business can reduce taxable income legally and stay fully compliant with IRAS rules – all while saving money.
General Rules for Claiming Allowable Business Expenses

Expenses must be wholly and exclusively for producing business income. To apply this correctly, follow these IRAS guidelines:
- Follow the ‘Incurred’ Rule (Accrual Basis): Claim expenses in the financial year they are incurred, not when paid.Example: An invoice received in December 2023 but paid in January 2024 belongs to the 2023 Year of Assessment.
- Watch Out for Prohibited Expenses (Section 15): Certain costs, like private car expenses (S-plated cars), cannot be claimed, even if used for client meetings. Petrol, parking, or ERP charges for private cars are disallowed.
- Apportion Mixed Expenses: For costs used partly for business and partly personal (e.g., home electricity bills), claim only the portion strictly for business.
- Digitize Your Records: Keep records for at least 5 years. Digital copies via accounting software are accepted and prevent fading or loss.
- Ensure ‘Arm’s Length’ Transactions: Payments to related parties (e.g., spouse) must be reasonable and reflect market rates. Overstated payments can be challenged by IRAS.
Following these rules protects your business from penalties and makes tax filing easier and more transparent.
Deductible vs Non-Deductible Business Expenses Under IRAS
Understanding the difference between deductible and non-deductible expenses is essential for accurate tax filing in Singapore. Under IRAS rules, only expenses wholly and exclusively incurred in the production of business income can be deducted from gross income.
Correct classification helps businesses reduce taxable income legally while remaining fully compliant with the Singapore Income Tax Act.
Examples of Deductible Business Expenses
Deductible expenses are day-to-day operational costs that support business activities.
Employee-Related Costs
- Salaries, bonuses, and employer CPF contributions
- Staff medical expenses (subject to the 1% or 2% remuneration cap)
- Employee training and skills-upgrading courses
Operational Overheads
- Office or shop rent, property tax, and utilities
- Work-from-Home (WFH) expenses: incremental electricity or telecom costs attributable to business use
Professional Services
- Fees paid to accountants, tax agents, and lawyers
- Company secretarial and statutory audit fees
Marketing and Finance
- Advertising and promotion (social media ads, SEO, print ads)
- Bank charges and interest on business-related loans
Repairs and Maintenance
- Repairs to business premises
- Maintenance of office equipment to keep them operational
These expenses are deductible provided they are reasonable, business-related, and properly supported by documentation.
Examples of Non-Deductible Business Expenses
Non-deductible (disallowable) expenses must be added back when computing taxable income.
Private and Personal Expenses
- Personal meals, holidays, or family entertainment
- Personal life or health insurance premiums
- Home-to-office commuting costs
Private Car Expenses (S-Plated Cars)
- Petrol, parking, ERP, insurance, and maintenance
IRAS strictly disallows all private car expenses, even if used for client meetings.
Capital Expenditures
- Purchase of fixed assets (machinery, vehicles, office furniture) (Claimable via Capital Allowances, not as direct expenses)
- Trademark or patent registration (unless under approved tax incentive schemes)
- Office renovation or refurbishment costs (covered under Section 14N)
Fines and Penalties
- Traffic fines
- Late filing penalties imposed by IRAS or ACRA
- Penalties arising from legal or regulatory breaches
Prohibited Entertainment
- Entertainment with no clear business purpose or documented business discussion
Understanding these distinctions helps businesses avoid over-claiming, reduce audit risk, and maintain clean, compliant tax records.
Revenue Nature vs Capital Expenditure: How IRAS Determines Deductibility

IRAS determines whether a business cost is deductible based on its nature—whether it is revenue or capital in nature. Distinguishing between the two is essential for accurate tax filing and compliance with the Singapore Income Tax Act.
Revenue Nature (Generally Deductible)
Revenue expenses are recurring, day-to-day operating costs incurred wholly and exclusively to generate business income. Common examples include:
- Rent, utilities, and office stationery
- Salaries, bonuses, and employer CPF contributions
- Marketing, advertising, and professional fees
- Routine repairs that maintain assets without improving or extending their useful life
These expenses are generally deductible in the year they are incurred, provided they are reasonable, business-related, and supported by proper records.
Capital Expenditure (Not Deductible as Expenses)
Capital expenses relate to long-term assets or expenditures that provide enduring benefits to the business. Typical examples include:
- Purchase of machinery, office furniture, or IT equipment
- Incorporation and business setup costs
- Renovations or improvements that increase an asset’s value or extend its useful life
Capital expenses cannot be deducted directly from income. Instead, qualifying assets may be claimed over time through Capital Allowances, in accordance with IRAS rules.
Partial and Special Allowable Business Expenses Under IRAS
Some business expenses are only partially deductible or subject to specific conditions and limits under IRAS rules. These expenses require extra care to ensure claims are accurate and compliant.
COE for motor vehicles
Under IRAS rules, the Certificate of Entitlement (COE) is treated as part of a vehicle’s capital cost rather than an operating expense. Its deductibility depends strictly on the classification of the vehicle:
- Private Cars (S-plated, RU-plated, and Company Cars): Generally, no Capital Allowance (CA) is allowed for the vehicle or its COE. This remains true even if the car is used for business meetings. The only exceptions are vehicles used for specific trades, such as private hire cars or driving instruction vehicles.
- Commercial Vehicles (e.g., Vans, Lorries, Motorcycles): If the vehicle is used for business, both the initial COE cost and any subsequent COE renewal costs are qualifying capital expenditures. These costs are claimed through Capital Allowances over the asset’s useful life, rather than being deducted as a one-time business expense.
- Unused COE: If a COE is purchased but not used to acquire a vehicle (e.g., due to forfeiture or expiration), the cost is not deductible as it is considered a capital loss.
Private Car / S-Plated Car Expenses
Under IRAS rules, all expenses relating to private cars (S-plated cars) are not deductible, even if the vehicle is used partly or fully for business purposes.
Non-deductible expenses include:
- Petrol or EV charging costs
- Parking fees and ERP charges
- Road tax, insurance, and maintenance
- Repairs, depreciation, and COE costs
These expenses cannot be claimed, either as business expenses or through Capital Allowances.
Exception: Only vehicles registered and used as private hire cars (PHV) or driving instruction vehicles may qualify for tax deductions, subject to IRAS conditions.
Businesses should exclude all private car costs when computing taxable income to avoid disallowed claims and IRAS penalties.
Renovation & Refurbishment Expenses
Renovation and refurbishment (R&R) costs can be tax deductible under Section 14N, as long as the works do not affect the building structure (e.g. interior upgrades, fittings, repainting).
- Tax deduction cap: SGD 300,000 per 3-year period Applicable to SMEs, sole proprietors, and partnerships
- For sole proprietors: the cap applies per individual, regardless of the number of businesses
- For partnerships: the cap applies at the partnership level
Ideal for businesses upgrading offices, shops, or commercial spaces to support daily operations.
Research & Development (R&D) Expenditure
R&D expenses are tax deductible only if your business is the beneficiary of the R&D activities. Merely performing R&D work is not sufficient.
Your business can claim R&D deductions if it:
- Bears the financial risk of the R&D; and
- Owns and can commercially use the resulting know-how or intellectual property (IP).
Key restrictions:
- Businesses providing R&D services for clients cannot claim R&D deductions, unless the R&D is done for their own business.
- R&D expenses must be declared under “Allowable Business Expenses” in Form B (Self-Employed) or Form P (Partnership).
Proper documentation of R&D scope and costs is required to support IRAS claims.
Medical Expenses Cap
Medical expenses provided to employees are tax deductible, but they are subject to a strict cap under IRAS rules to ensure the benefits remain reasonable.
- Standard Cap (1%): Tax deductions for medical costs are generally limited to 1% of the total employee remuneration (including salaries, allowances, bonuses, and CPF contributions) for the relevant Year of Assessment.
- What’s Included: This cap covers outpatient treatments, hospitalization costs, and medical insurance premiums paid by the employer.
- Enhanced Cap (2%): The deduction limit can be increased to 2% if the company implements approved schemes like the Portable Medical Benefits Scheme (PMBS) or the Transferable Medical Insurance Scheme (TMIS).
- Compliance: To be deductible, these benefits must be part of the employment terms and supported by proper documentation, such as original invoices, receipts, and payment records.
How Allowable Expenses Reduce Taxable Income

Allowable business expenses help reduce your company’s taxable income, which in turn lowers the amount of corporate tax payable to IRAS.
In simple terms, tax is calculated on net profit, not total revenue:
Taxable Income = Gross Income – Allowable Business Expenses
When eligible expenses such as rent, salaries, utilities, marketing costs, or approved deductions (e.g. R&D, R&R, medical expenses) are properly claimed, your chargeable income decreases, resulting in lower tax liability.
Why this matters:
- Reduces corporate tax payable
- Improves cash flow
- Ensures compliance with IRAS regulations
Accurate expense classification and proper documentation are essential to maximise deductions while avoiding IRAS penalties or audits.
Common Mistakes & IRAS Audit Triggers
Many businesses unintentionally make errors when claiming allowable expenses, which can increase the risk of an IRAS audit or tax adjustment.
Common Mistakes Businesses Make:
- Claiming personal expenses as business costs (e.g. private meals, personal transport)
- Deducting capital expenses (equipment, renovations, vehicles) as revenue expenses
- Over-claiming private car or medical expenses beyond IRAS limits
- Missing or incomplete supporting documents (invoices, receipts, contracts)
- Claiming expenses that are not wholly and exclusively incurred for business purposes
Common IRAS Audit Triggers:
- Unusually high expense ratios compared to revenue
- Repeated claims for restricted or partially deductible expenses
- Inconsistent figures across tax filings and financial statements
- Large deductions without clear business justification
Proper expense classification, clear documentation, and understanding IRAS rules can significantly reduce audit risks and help your business stay fully compliant.
How Koobiz Helps Businesses Comply with IRAS Allowable Expense Rules
Koobiz assists businesses in navigating strict IRAS regulations while maximizing legitimate tax deductions through our specialized solutions:
- Correct expense classification: Deductible, partially deductible, or non-deductible
- Audit-ready records: Invoices, receipts, and supporting documents
- Expert guidance: Private car costs, R&D, renovation, and medical benefits
- End-to-end support: From bookkeeping to tax filing
Partner with Koobiz today to ensure your tax filings are accurate, fully compliant, and optimized for maximum savings. Let us handle the complexities while you focus on growing your business.
FAQs: Practical Questions Business Owners Ask
What business expenses are 100% deductible?
Expenses incurred wholly and exclusively for business purposes are generally deductible, including staff costs, office expenses, professional fees, routine maintenance, and qualifying R&D expenses under IRAS rules.
What expenses cannot be claimed as business deductions?
Personal expenses, private car costs (S- or RU-plated vehicles), capital assets not claimed via capital allowances, fines, penalties, and dividends are not deductible under IRAS guidelines.
What should businesses do to ensure expenses are tax-deductible?
Businesses must ensure all expenses are incurred wholly and exclusively for business purposes, with no personal element included. Furthermore, every claim must be supported by proper invoices and original records maintained for at least 5 years as required by IRAS.






































