Tax
How to Declare Side Income in Singapore: A Tax Guide for Employees
Earning on the side while employed? Here is how IRAS treats side income, which form to file, what you can deduct, the MediSave rule for self-employed income, and how to keep clean records.
By the Giinger team · Updated · 3 min read
Earning money on the side is exciting. Then April comes, and the question appears: how do I declare this?
The good news: Singapore's system is simple once you know the steps. This guide explains them in plain English.
This is general information, not tax advice. Check the IRAS website for the current rules, or ask a tax adviser for your case.
Yes, side income is taxable
If you are a Singapore tax resident, income from these activities is generally taxable:
- Freelance work for clients.
- Revenue from an app or software product.
- Consulting fees.
- Commissions and other business income.
IRAS treats this as trade income (or business income), separate from your employment income.
Your employer reports your salary to IRAS automatically. Nobody reports your side income for you. You must declare it yourself.
Which form to file
- Form B is for individuals who have trade or business income. If you have side income, this is usually your form.
- Form B1 is for tax residents who do not have trade or business income.
When you log in to myTax Portal, IRAS shows you the form that applies. If you started a side business this year, make sure you declare the trade income, even if you only received a Form B1 notice before.
What you need to report
For your side business, you report:
- Revenue: everything you received.
- Gross profit, if you sell goods.
- Allowable business expenses.
- Adjusted profit or loss.
If your yearly revenue is below S$200,000, IRAS generally lets you submit a simple 4-line statement with these numbers instead of full accounts. You must still keep the records behind them.
What you can deduct
Expenses are deductible if they are wholly and exclusively for the business. Common examples for side projects:
- Software subscriptions used for the work.
- Developer program fees (App Store, Google Play).
- Hosting, domains and cloud services.
- Equipment used only for the business.
- Fees paid to a contracting partner.
- Professional fees, such as accounting.
Personal costs are not deductible. Mixed costs, like a phone used for both, need a fair split.
The MediSave rule
If your annual net trade income is more than S$6,000, you are generally required to make MediSave contributions as a self-employed person.
The amount depends on your income and age. IRAS and CPF send you a notice after your tax assessment. Pay it on time to avoid penalties.
Keep records for five years
IRAS can ask for your records. Keep, for at least five years:
- Invoices you sent.
- Contracts with clients.
- Bank statements showing payments.
- Receipts for expenses.
- The SGD value of any foreign currency payments.
A separate bank account for side income makes this much easier.
Common mistakes
- Thinking small amounts do not count. Even small side income should be declared.
- Mixing personal and business money. It makes your records hard to prove.
- Forgetting foreign income. Overseas clients paying into a Singapore account still count. See how to invoice overseas clients.
- Missing the MediSave notice.
- Filing late. Late filing can lead to penalties.
A simple yearly routine
- Every month: save invoices and receipts in one folder.
- Every quarter: check revenue and expenses so there are no surprises.
- In March: total the year and prepare your 4-line statement.
- In April: file on myTax Portal before the deadline.
- After assessment: pay income tax and MediSave on time.
How Giinger fits in
When you work through Giinger, the client pays Giinger. Giinger keeps its agreed fee and pays you under a written service contract, with a clear monthly record.
That record makes your tax return easier. You still declare the income yourself.
Before you start, also check your employment terms. See can you have a side business while employed in Singapore.
Frequently asked questions
Do I have to declare side income in Singapore?
Yes. If you are a Singapore tax resident, income from a side business, freelance work or a side project is generally taxable and must be declared to IRAS, even if your employer already reports your salary.
Which tax form do I use if I have side business income?
Individuals with trade or business income, including side income, generally file Form B. Form B1 is for tax residents without trade income. Your form type is shown when you log in to myTax Portal.
When is the tax filing deadline in Singapore?
Individual tax returns are usually due in April each year, with a later date for e-filing than for paper filing. Check the current deadline on the IRAS website.
Do I need to pay MediSave on my side income?
If your annual net trade income from self-employment is more than S$6,000, you generally need to make MediSave contributions as a self-employed person. IRAS and CPF will tell you the amount.
If I work through Giinger, do I still pay tax?
Yes. Giinger pays you under a written service contract and gives you a clear monthly record. You declare that income in your own tax return.
This guide is general information, not legal, tax, immigration or employment advice. Rules change; check the official sources linked above or a qualified adviser for your own situation.