The Inland Revenue Authority of Singapore will implement a new tax reference number format for Estates, Trusts and Unit Trusts from July 2026.
The existing 10-character Income Tax Reference ID will be replaced by a 9-character ASGD ID in the format AXXXXXXXX.
Key Impacts
Tax administration and correspondence
Executors, administrators, legal personal representatives, trustees and tax agents should use the new ASGD ID when communicating with IRAS or submitting tax-related documents. This will become the primary identifier for the affected trust entities.
Transition of IRAS notices and records
During the system transition, some IRAS correspondence may continue to display the existing Income Tax Reference ID. Firms should be aware that both identifiers may appear in tax records until the change is fully reflected across IRAS systems.
Compliance and filing processes
Tax agents and fiduciaries should update internal records, client master data, filing checklists and correspondence templates to include the ASGD ID. This is particularly relevant for firms managing multiple estates, private trusts or unit trust structures.
Audit and documentation considerations
Auditors and accountants should ensure that tax reference numbers used in working papers, tax computations and supporting schedules are consistent with the latest IRAS records. Where both old and new identifiers appear during the transition period, cross-referencing should be maintained to avoid confusion.
Practical Issues
- System updates: Tax software, client databases, document management systems and workflow tools may need to be updated to capture the new 9-character format.
- Client communication: Trustees, executors and legal representatives should be informed of the change, especially where they handle IRAS correspondence directly.
- Record matching: Firms may need to reconcile old Income Tax Reference IDs with new ASGD IDs during the transition period.
- Notice review: Tax notices received before January 2027 should be checked carefully, as some may still display the old reference number while IRAS system upgrades are ongoing.
- Process controls: Firms should consider updating review procedures to ensure the correct identifier is used in filings, payments, enquiries and authorisation forms.
Action Points
Accounting firms, tax agents and fiduciaries should monitor notifications from IRAS and update client records once the new ASGD ID is issued. Internal tax administration processes should allow for both the old and new identifiers during the transition period. By January 2027, the ASGD ID is expected to fully replace the existing tax reference number in IRAS tax notices.
Source: IRAS website, 29 June 2026