Compliance

Singapore IRAS Alters Tax Reference Numbers for Estates, Trusts & Unit Trusts: What You Must Know

Singapore’s IRAS is replacing “ITR ID” with a new 9-character “ASGD ID” for Estates, Trusts and Unit Trusts from mid-2026 ahead of full digital service rollout in 2027.

By NomadicTax Research Team • 5-8 min read • August 31, 2026

## What’s Changing - **Old reference number (ITR ID)**: 10 characters (e.g. `3000123456` / `330012345X`). - **New reference number (ASGD ID)**: 9 characters in format `AXXXXXXXX`. IRAS will issue these to Estates, Trusts and Unit Trusts with ongoing tax filing obligations. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) - Transition period: From notification until end-December 2026, IRAS systems may still accept the old ITR ID on some notices. But from **January 2027**, all notices will exclusively use the ASGD ID. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) ## What You Must Do Now If you are an executor, administrator, legal personal representative, trustee, or tax agent: - Update your internal records (accounting software, templates etc.) to use ASGD ID once issued. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) - Appoint a **Corppass Administrator** by **31 December 2026** if you’ll use future e-filing digital services for Form T or Form UT. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) - If you don’t reside in Singapore or don’t hold NRIC/FIN, you may appoint a Singapore representative to act as your Corppass Administrator under authorization letter. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) - Inform your tax agent(s) of the new ASGD ID so they can update their records. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) ## Why It Matters - Facilitates upcoming **digital service enhancements** in 2027, including e-filing of Form T and Form UT via myTax Portal and management via Corppass. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) - Improves **security** and **operational efficiency** by standardizing reference formats. Old ITR IDs will be phased out. ([iras.gov.sg](https://www.iras.gov.sg/taxes/other-taxes/trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts/change-of-tax-reference-numbers-for-estates--trusts--unit-trusts?utm_source=openai)) ## Practical Example Suppose you are trustee of “Green Trust”. Previously, IRAS issued an ITR ID `3001234567`. From July 2026 onwards, IRAS notifies you of ASGD ID `A12345678`. You need to: - Use **A12345678** for all filings/payments/communications with IRAS from the moment it’s issued. - By **31 Dec 2026**, ensure your Corppass Administrator is appointed, or your Singapore representative if you’re abroad. - From January 2027, you cannot use the old ITR ID at all—it will no longer be valid. ## Key Dates at a Glance | Date | Action | |---|---| | July 2026 | ASGD IDs start issued; transition begins. | | 31 Dec 2026 | Deadline to appoint Corppass Administrator and full transition prep. | | January 2027 | All notices use only ASGD ID; ITR ID retired. | --- **Summary**: If you manage or represent an Estate, Trust or Unit Trust in Singapore, now is the time to update your systems, appoint your digital admin (Corppass), and prepare for the full rollout of new IDs early next year.