Handle S45 withholding tax yourself
Recognize payments to non-residents that trigger withholding at source, let the bill flow flag them, and file and pay IRAS by the 15th of the second month.
Who can do this
Finance operator prepares; Organization Admin approves
Primary route
/finance/filings
Last verified
5 August 2026
- Supplier records that identify non-resident counterparties
- Corppass access to myTax Portal (S45) for the submitter
01
Recognize a withholding payment
Certain payments to non-resident companies and individuals are taxed at source: the payer withholds a percentage and remits it to IRAS. Typical triggers are interest, royalties, technical and management service fees for work performed in Singapore, equipment rental, and non-resident director remuneration.
- Rates differ by payment type and can be reduced by a double-tax agreement — the treaty position is a judgment call worth professional confirmation the first time each counterparty type appears.
- Withholding is the payer’s liability: failing to withhold does not shift the tax to the supplier.
02
Flag it when the bill is entered
The bill flow carries S45 classification, so withholding is decided when the liability is recorded — not discovered at payment time.
- Mark the counterparty as non-resident on the contact record.
- When entering the bill, set the S45 payment classification; the withholding computes on the gross amount at the applicable rate.
- Post the bill: the payable splits into the net amount due to the supplier and the withholding due to IRAS.
- Pay the supplier the net; the withheld portion sits in the S45 liability until filed.
03
File and pay by the deadline
The S45 filing and payment are due by the 15th of the second month following the date of payment to the non-resident.
- Open Finance → Reports → Filings; the S45 obligation row aggregates the period’s withholding events.
- Prepare and validate the filing draft, then submit via the connected channel or file in myTax Portal and mark the row manually filed.
- Pay IRAS the withheld amount by the same deadline and attach the acknowledgement.
- Issue the supplier their certificate of tax deducted where requested.
The clock runs from the payment date to the non-resident, not the invoice date — a bill paid in January is filed and settled by 15 March.
Troubleshooting
- Not sure a payment is caught: check the IRAS payment-type list before paying — withholding cannot be applied retroactively without cost.
- Treaty rate claimed without documentation: keep the counterparty’s certificate of residence on the contact record; IRAS can ask for it.
- Missed deadline: file and pay immediately — late payment attracts penalties that escalate monthly.