A mixed GST invoice review should connect each line to the actual supply and supporting tax treatment before the document is approved. A total showing one GST amount does not explain why different items were classified differently. Ask the accountant to review the line-level facts rather than applying the first line’s tax code to everything.

Accounting records, calculator and glasses on a desk
Illustrative photograph by Cht Gsml.

Identify the document and supplies

Record the supplier, customer, invoice reference and currency. Separate goods, services, deposits, discounts and other components as applicable. Keep the underlying agreements or delivery evidence needed to understand what each line represents.

Do not infer zero-rating or exemption merely because a line shows no GST. A missing tax amount, an out-of-scope item and a supported different treatment are separate possibilities.

Prepare a line-level schedule

Show the description, value, tax code, GST amount and supporting reference for each relevant component. Reconcile line totals with the document total and any rounding. Preserve the received invoice rather than editing the supplier’s PDF.

Give the reviewer the facts needed to assess the correct treatment and document requirements, including whether a separate document is required for a particular supply. This checklist does not establish that every type of mixed supply may use one invoice.

Example: one line lacks an explanation

An invoice contains a standard-rated item and another line marked exempt with no supporting description. Request clarification through the verified supplier channel. Do not claim or remove tax solely to make the purchase ledger agree with a preferred total.

Keep return mapping traceable

Retain the accepted classification and any corrected invoice with the original. Review input-tax conditions or output-tax reporting separately as appropriate. The schedule should explain how the invoice reaches the accounting records and GST return without inventing a universal tax shortcut.

Related practical guidance

For the surrounding records and responsibilities, see bookkeeping basics, company records to keep, bookkeeping and accounting.

Official guidance: IRAS official guidance.

Help with your company records

For accounting, bookkeeping and related compliance support, contact Raffles Corporate Services at [email protected] or WhatsApp +65 8501 7133. Tell us which records or process need attention so we can discuss the relevant next steps.