Singapore GST F5 Return — Quarterly GST Compliance

Confirm the client is GST-registered with IRAS, establish the return period (quarterly by default, monthly for large businesses with taxable turnover above SGD 5 million), verify the GST registration number (UEN or M-format), and check for any special registration type — standard, voluntary, group, or overseas vendor. Flag immediately if the client is in a GST group registration (refusal R-SG-2) or has a partial-exemption position that may exceed the de minimis threshold (refusal R-SG-1).

Gather the minimum viable inputs — at minimum a full-period bank statement from a Singapore business bank (DBS, OCBC, UOB, Standard Chartered, HSBC Singapore, or similar). Request sales invoices for any zero-rated international services or exports, purchase invoices for input tax claims above SGD 300, the prior-period GST F5 (to pick up any brought-forward excess input tax), and customs import permits for any goods imported via Singapore Customs. Identify any imported-service suppliers (non-resident SaaS, professional services) that will require reverse-charge treatment under Section 14(2) of the GST Act.

Classify every bank statement line into one of: standard-rated domestic supply (9%, Box 1/6 for sales or Box 5/7 for purchases), zero-rated supply (0%, Box 2), exempt supply (Box 3), out-of-scope exclusion, or reverse-charge imported service (Box 14/6/7). Apply the supplier pattern library for deterministic lines, then apply Tier 1 rules for unambiguous cases. Raise Tier 2 questions for ambiguous lines (motor car vs commercial vehicle, residential vs commercial rent, mixed-use phone, entertainment vs staff welfare meal, SaaS entity identity). Apply blocked-input rules under Regulations 26–27 of the GST (General) Regulations: motor car running costs, club membership fees, and medical expenses are permanently blocked with no recovery.

Review all imported services from non-resident suppliers identified in Phase 2. For each, self-assess output tax at 9% in Box 6 and corresponding input tax in Box 7 (net zero for a fully taxable business), and report the value in Box 14. From 1 January 2023, also check for imported low-value goods (goods valued at SGD 400 or below purchased from overseas vendors via electronic marketplaces) — if the overseas vendor or electronic marketplace is not GST-registered in Singapore, the recipient must self-assess. Verify deemed-supply rules: gifts to any recipient exceeding SGD 200 in a 12-month period trigger output tax at 9%; private use of business assets must also be assessed.

Aggregate the classified transaction register into the nine boxes of the GST F5: Box 1 (standard-rated supplies), Box 2 (zero-rated supplies), Box 3 (exempt supplies), Box 4 (total value of taxable supplies = Box 1 + 2), Box 5 (taxable purchases), Box 6 (output tax due), Box 7 (input tax claimed), Box 8 (net GST payable or refundable = Box 6 minus Box 7), Box 14 (total value of imported services and low-value goods subject to reverse charge). Cross-check Box 4 against total revenue per the management accounts or sales register. Reconcile Box 5 against total purchases per the bank statement. Identify any credit notes from prior periods and apply the SGD 1,500 threshold — errors up to SGD 1,500 net GST adjust in the current return; errors above SGD 1,500 require a separate GST F7 voluntary disclosure.

Produce a concise reviewer brief summarising any judgement calls made during classification (zero-rated international service confirmations, reverse-charge amounts, any Tier 2 questions and client responses), listing any items excluded from input tax recovery and the regulatory basis (Reg 26/27 blocks), and flagging any items requiring further professional attention (partial exemption apportionment, GST group issues, or prior-period errors above SGD 1,500). The return is filed electronically via myTax Portal (https://mytax.iras.gov.sg) — no paper filing is accepted. The due date is one month after the end of the accounting period (e.g. 31 January for a quarter ending 31 December). Payment of net GST is due on the same date as filing.