When can I zero-rate a service to an overseas client?

When the supply meets the international-services conditions in section 21(3) of the GST Act — broadly, the client belongs outside Singapore and the benefit accrues outside Singapore, subject to the specific limbs. HelloBooks records the belonging status and service nature on the engagement so the zero-rating is evidenced.

What is Section 45 withholding tax and does it apply to me?

Section 45 requires you to withhold tax on certain payments to non-residents — interest (15%), royalties (10%), management/technical fees (17%) and non-resident director fees (22%), unless a DTA reduces the rate. HelloBooks computes the withholding, applies DTA rates where a Certificate of Residence is provided, and tracks the payment deadline to IRAS.

Can HelloBooks handle retainer and milestone billing with the right GST tax point?

Yes. It supports retainer schedules, milestone invoices and time-based billing, and applies the GST time-of-supply rules so output GST falls in the correct F5 quarter even when the cash and the work are in different periods.

Singapore · Professional services

Accounting software for Singapore professional-services firms

Zero-rating of international services, reverse charge on imported services, Section 45 withholding tax on non-resident payments, retainer billing, and the IRAS GST F5 — for Singapore consultancies and advisory firms.

SingaporeLast updated: 2026-07-10

Start free See Singapore pricing

The short answer

For Singapore professional-services firms, two statutory questions come up constantly: is a service to an overseas client zero-rated as an international service, and does a payment to a non-resident trigger Section 45 withholding tax? Get the first wrong and you either overcharge GST or under-declare it; get the second wrong and IRAS holds you liable for the tax you failed to withhold. HelloBooks makes the GST treatment explicit on every invoice, computes Section 45 withholding on qualifying payments, and prepares the GST F5 from your ledger.

The facts

Singapore professional services at a glance

Field	Value
Authority	Inland Revenue Authority of Singapore (IRAS) GST and withholding tax both administered by IRAS.
Services to SG clients	9% GST Standard-rated.
International services	Zero-rated (0%) Where the section 21(3) conditions are met.
Imported services	Reverse charge Self-accounted where input tax recovery is not full.
Section 45 WHT	10–22% (statutory) Royalties 10%, interest 15%, mgmt/technical fees 17%, director fees 22%; DTA may reduce.
Registration threshold	S$1 million Compulsory; voluntary registration common for B2B firms.

Rates and thresholds verified against IRAS as at 2026-07-10. Re-verify after each Singapore Budget.

Zero-rating international services

A service supplied to an overseas client can be zero-rated as an international service where it meets the conditions in section 21(3) of the GST Act — broadly, the service is supplied to a person who belongs outside Singapore and directly benefits a person outside Singapore, subject to the specific limbs of the section. A service to a Singapore client is standard-rated at 9%.

HelloBooks records the client's belonging status and the nature of the service on the engagement, applies the resulting GST treatment to each invoice, and flags zero-rated international-service lines for review so the position is documented, not assumed.

Section 45 withholding tax on non-resident payments

When a Singapore firm pays a non-resident for interest, royalties, management or technical fees, or non-resident director fees, Section 45 of the Income Tax Act requires tax to be withheld at the statutory rate (10% royalties, 15% interest, 17% management/technical fees, 22% director fees) unless a Double Tax Agreement reduces it and the payee provides a Certificate of Residence. The withheld tax is due to IRAS by the 15th of the second month after the payment.

HelloBooks computes the Section 45 withholding on qualifying payments, applies the DTA-reduced rate where a Certificate of Residence is on file, and tracks the payment deadline — so a withholding obligation never slips.

Frequently asked

Questions Singapore professional services ask

Other Singapore industry guides

For e-commerce sellers For food & beverage

Singapore

GST & the IRAS GST F5

9% GST, the S$1M threshold, reverse charge and the F5 return.

Plans

Singapore pricing

SGD billing, GST F5 preparation included on every paid plan.

Capabilities

All features

Accounting, GST, banking, inventory, AI assist.

HelloBooks prepares the IRAS GST F5 return from your ledger — standard-rated, zero-rated and exempt supplies, reverse charge on imported services, and input tax — plus Section 45 withholding tax on non-resident payments. For advisory firms it also computes Section 45 withholding tax on non-resident payments with DTA-reduced rates where a Certificate of Residence applies.