Assumptions and sources
These rules are stored separately from the calculations. Each shows its effective date and when it was last checked. Rules marked “to verify” are best available values that you should confirm. Current rules are held constant into the future; nothing here updates automatically.
| Rule | Value | Effective | Status | Source |
|---|---|---|---|---|
Ordinary Wage ceiling (monthly) | S$7,400 | 2025-01 to 2025-12 | official checked 2026-10-21 | Official page |
Ordinary Wage ceiling (monthly) Held constant after 2026; later changes are not announced. | S$8,000 | 2026-01 onwards | official checked 2026-10-21 | Official page |
Annual wage ceiling for Additional Wage AW ceiling = S$102,000 minus total Ordinary Wages subject to CPF in the year. | S$102,000 | 2016-01 onwards | official checked 2026-10-21 | Official page |
CPF OA base interest (p.a.) Computed monthly on the lowest balance, credited annually in December. Extra interest goes to SA/RA and is excluded. | 2.5% | 1999-01 onwards | official checked 2026-10-21 | Official page |
Contribution and OA allocation rates (SC / 3rd-year PR) Rates for 55 and above shown for completeness; those projections are flagged for manual assessment. | 6 rows | 2026-01 onwards | official checked 2026-10-21 | Official page |
PR graduated rates (G/G), below 55 OA allocation for years 1-2 estimated pro-rata to full-rate allocation. | year1: {"employer":0.04,"employee":0.05} · year2: {"employer":0.09,"employee":0.15} | 2026-01 onwards | to-verify checked 2026-10-21 | Official page |
HDB concessionary loan rate Pegged to OA rate + 0.1%; reviewed quarterly. | 2.6% | 2016-01 onwards | official checked 2026-10-21 | Official page |
HDB loan assessment interest floor Used only for capacity assessment, not repayment. | 3% | 2023-08 onwards | to-verify checked 2026-10-21 | Official page |
Mortgage Servicing Ratio cap | 30% | 2013-01 onwards | official checked 2026-10-21 | Official page |
Max loan-to-value (HDB loan) | 75% | 2024-08 onwards | official checked 2026-10-21 | Official page |
Max HDB loan tenure (years) | S$25 | 2013-01 onwards | official checked 2026-10-21 | Official page |
Tenure ends by income-weighted age | S$65 | 2013-01 onwards | official checked 2026-10-21 | Official page |
HDB loan household income ceiling (families) | S$14,000 | 2019-09 onwards | official checked 2026-10-21 | Official page |
HDB loan income ceiling (singles) | S$7,000 | 2019-09 onwards | official checked 2026-10-21 | Official page |
Max OA you may keep when taking an HDB loan OA above this must go to the purchase before the loan. | S$20,000 | 2013-01 onwards | official checked 2026-10-21 | Official page |
Downpayment due at Agreement for Lease (HDB loan) Full 25% downpayment modelled at AfL unless staggered downpayment applies. | S$1 | 2024-08 onwards | to-verify checked 2026-10-21 | Official page |
Share of downpayment at AfL under Staggered Downpayment Only for eligible first-timer households; remainder at key collection. | 50% | 2024-08 onwards | to-verify checked 2026-10-21 | Official page |
Option / booking fee Paid in cash; counted toward the downpayment. | 2-room Flexi: 500 · 3-room: 1,000 · 4-room: 2,000 · 5-room: 2,000 · 3Gen: 2,000 | 2020-01 onwards | official checked 2026-10-21 | Official page |
Deferred Income Assessment initial downpayment 2.5% of flat price for eligible couples buying an uncompleted flat; booking fee counts toward it. Stamp duty and fees remain due. Remaining downpayment is due at keys. | 2.5% | 2024-06 onwards | official checked 2026-10-21 | Official page |
Deferred Income Assessment eligibility At HFE application: at least one full-time student/NSF or completed studies/NS within 12 months; at least one aged 30 or below; married/fiancé-fiancée couple; at least one first-timer. Before July 2025 both applicants needed the student/NS condition. | maxAge: 30 · recentCompletionMonths: 12 · qualifyingApplicants: 1 | 2025-07 onwards | official checked 2026-10-21 | Official page |
Deferred income assessment planning timing HDB assesses about three months before flat completion, not necessarily keys. Planner uses keys minus three months and projected trailing 12-month income as an approximation, never an approved HFE amount. | monthsBeforeKeys: 3 · incomeWindowMonths: 12 | 2024-06 onwards | estimate checked 2026-10-21 | Official page |
BTO income ceiling Some flat types and schemes have different ceilings; verify for your project. | family: 14,000 · single: 7,000 | 2019-09 onwards | to-verify checked 2026-10-21 | Official page |
Enhanced CPF Housing Grant (first-timer families) Disbursed into OA at key collection and applied to the flat price. Singles receive half, income ceiling S$4,500. | 16 rows | 2023-02 onwards | to-verify checked 2026-10-21 | Official page |
Buyer's Stamp Duty marginal bands | 6 rows | 2023-02 onwards | official checked 2026-10-21 | Official page |
Legal fees, Home Protection and fire insurance Rough estimates; HDB states exact amounts in your payment letters. | conveyancingPct: 0.001 · conveyancingMin: 400 · keysLegal: 500 · hpsAnnualPer100k: 250 · fireInsurance: 10 | 2024-01 onwards | estimate checked 2026-10-21 | Official page |
Deferred Income Assessment uses preliminary eligibility checks and a 2.5% initial downpayment for qualifying uncompleted flats. Future income, loan and grant projections require HDB reassessment; completed-flat deferred-income cases need manual verification.
Not modelled in this release: bank loans, resale grants, Proximity and Step-up grants, and households where an applicant reaches 55 during the projection (flagged for manual assessment).
Planning estimates only. Eligibility, grants and financing remain subject to HDB, CPF Board and lender assessment.