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Estate, Trust & Unit Trust Tax Reference Number Change in Singapore: What Fiduciaries Need to Do
Singapore’s IRAS is replacing the ITR ID with a new ASGD ID for estates, trusts and unit trusts from July 2026 — here's what executors, trustees and agents should know and how to prepare.
By NomadicTax Research Team • 5-8 min read • August 17, 2026
## Background and What’s Changing
From **July 2026**, the Inland Revenue Authority of Singapore (IRAS) is phasing out the old **10-character tax reference number (ITR ID)** for **Estates, Trusts, and Unit Trusts**, replacing it with a **9-character ASGD ID** in the format `AXXXXXXXX`. ([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))
This revamp is part of broader digital service upgrades scheduled to roll out in 2027, geared toward improved taxpayer experience and stronger security in tax administration. ([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 Timeline
| Time Period | What Applies |
|-------------|--------------------------|
| **From July 2026** | IRAS starts notifying active executors, administrators, legal personal representatives and trustees of their new ASGD IDs. Some notices may still show old ITR IDs during system upgrades. ([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)) |
| **Until December 2026** | Transitional period. Both ITR and ASGD IDs may appear, but ASGD should be used when notified. |
| **From January 2027** | All tax notices will use ASGD ID exclusively. Old ITR IDs will be discontinued. |
## What Trustees & Fiduciaries Must Do
- **Monitor correspondence**: Ensure you get notified of the new ASGD ID and retain proof of notification.
- **Update systems & documentation**:
- Banking standing instructions,
- Payment references,
- Legal documents, correspondence, internal records — wherever ITR IDs were used. |
- **Inform tax agents** if you engage them — they’ll need the new ASGD for filings and approvals. |
- **Verify payments**: During transition, IRAS will match ITR-based payments to correct accounts; starting January 2027, only ASGD will be accepted. Use it to avoid misapplied payments. |
## Why This Matters — Implications and Planning Tips
- **Compliance risk**: Using old ITR after Jan 2027 could lead to rejected filings or payment mismatches.
- **Operational smoothness**: Upgrading finance/accounting software and legal templates in advance prevents confusion or administrative delays.
- **Communication**: If you're a trustee or executor, inform beneficiaries, partners, and agents of the change to avoid mix-ups. |
## Practical Example
- **Trust X** with an ITR ID 3000123456 is notified in September 2026 of its new ASGD ID A12345678. Going forward:
- All payments must cite the new ASGD.
- Trustee updates banking and legal paperwork.
- Agent uses ASGD in all submissions.
- Until Dec 2026, if old ID still appears, IRAS will still map payments appropriately. At or after Jan 2027, only ASGD accepted. |
## Quick Checklist for Preparation
- Determine all documents, systems, and processes referencing **ITR IDs**.
- On receipt of ASGD, update every instance (bank, contracts, invoices, trust deeds).
- Run internal communication to ensure all staff or agents are aware.
- By **January 2027**, ensure no remaining use of ITR IDs in filings or payments. |
With proactive preparation, fiduciaries in Singapore can avoid mismatches, delays, or compliance penalties and enjoy a smooth transition into the digital service era.