Singapore's Ministry of Finance publishes a high level breakdown of revenue and expenditure on its website.
In the revised Financial Year 2021/2022 numbers distributed on Budget Day 18 February 2022, covering April 2021 to March 2022, operating revenue was $80.37 billion.
On top of this, there was also $20.33 billion net investment returns contribution (Up to 50% of the Net Investment Returns (NIR) on the net assets invested by GIC, MAS and Temasek; and, Up to 50% of the Net Investment Income (NII) derived from past reserves from the remaining assets), so broadly about a fifth of Singapore government gross income comes from investment returns. There is no breakdown provided for this - no surprise, since the reserves have always been a National Secret, so much so that even President Ong Teng Cheong, who was supposed to be the guardian of the reserves, faced a lot of difficulty getting information about them.
There is a breakdown provided for operating revenue. Figures in billions of dollars and percentage of operating revenue and gross income are:
| Revised FY2021 | $billion | % of Operating Revenue | % of Gross Income |
| OPERATING REVENUE | 80.37 | 100% | 80% |
| Corporate Income Tax | 17.51 | 22% | 17% |
| Personal Income Tax | 13.83 | 17% | 14% |
| Withholding Tax | 1.73 | 2% | 2% |
| Statutory Boards' Contributions | 2.86 | 4% | 3% |
| Assets Taxes | 4.6 | 6% | 5% |
| Customs, Excise and Carbon Taxes | 3.63 | 5% | 4% |
| Goods and Services Tax | 12.01 | 15% | 12% |
| Motor Vehicle Taxes | 2.39 | 3% | 2% |
| Vehicle Quota Premiums | 3.22 | 4% | 3% |
| Betting Taxes | 2.32 | 3% | 2% |
| Stamp Duty | 6.45 | 8% | 6% |
| Other Taxes | 5.46 | 7% | 5% |
| Fees and Charges (Excluding Vehicle Quota Premiums) | 3.44 | 4% | 3% |
| Others | 0.9 | 1% | 1% |
The top source of operating revenue is Corporate Income Tax at 22%, followed by Personal Income Tax at 17% and the Goods and Services Tax (GST - a Value Added Tax) at 15%.
Given the astronomical cost of private motor vehicles in Singapore, revenue from that is not as high as one might imagine, as Motor Vehicle Taxes and Vehicle Quota Premiums (aka Certificate of Entitlement or COE revenue, which you need to own a vehicle) combined account for only 7% of operating revenue. For the curious, "Motor Vehicle Taxes comprise additional registration fees, road tax, special tax on heavy-oil engines, passenger vehicle seating fees and non-motor vehicle licences, but exclude excise duties on motor vehicles which are classified under Customs, Excise and Carbon Taxes", so the true take from taxing motor vehicles is somewhat higher than 7%.