Invoicing and GST-ready accounting for electricians and plumbers in Singapore

Your technician finishes a rewiring job in Jurong at 6pm, texts you the parts used, and the invoice gets typed up on Saturday night — if it gets typed at all. Every day of delay pushes payment further out, and HDB and condo management offices will not chase you to pay them. Small jobs slip through completely, and by the time you notice, the customer barely remembers the visit.

A quote for a full bathroom re-pipe includes labour hours, PUB-compliant fittings, a licensed plumber's time and a helper — but the actual cost lands across a supplier invoice, a cash purchase at a hardware shop in Balestier and a timesheet in someone's head. Without job-level costing you cannot tell the profitable jobs from the ones you subsidised. Pricing the next quote becomes guesswork.

Circuit breakers, MCBs, PPR fittings, cable drums and copper pipe move between the store, two vans and a site, and nothing is written down. You reorder things you already have, and run out of the one part that holds up an urgent callout. Shrinkage on small high-value items is almost invisible until you count at year end and the numbers do not match.

If you are GST-registered, every quarter means digging out supplier tax invoices, separating standard-rated sales from any zero-rated or out-of-scope work, and reconciling it all before the GST F5 return is due. Cash jobs, deposits taken up front and progress billing on longer contracts each complicate the picture. Doing this in a spreadsheet is slow, and mistakes are expensive to unwind.

Build a quote on your phone from a saved price list of common jobs — socket installation, DB board replacement, water heater swap, choke clearing — and send it while you are still standing in the customer's kitchen. When they approve, the quote converts to a job and then to an invoice in one tap, with your GST registration number and GST breakdown already on it. Payment links and a clear due date go out with it, so the money starts moving the same day.

Attach parts, labour hours and subcontractor costs to a job as they happen, and Tallium AI shows you cost, price and margin per job rather than one lump figure at month end. Receipt scanning pulls supplier invoices and cash purchases in automatically and codes them to the right job, so nothing sits uncategorised. Over a few months you can see which work types actually pay — and quote the next one properly.

Treat each van as its own location, so you always know what stock is on the road and what is on the shelf. Issuing parts to a job reduces stock automatically, reorder points flag the fast-movers before they run out, and serial or batch tracking covers higher-value items like distribution boards and pumps. When a technician needs a part, you can tell them which van already has it instead of sending them to the supplier.

Sales and purchases are recorded with the correct GST treatment as they are entered, so your figures are ready when the GST F5 return is due rather than reconstructed from scratch. Bank feeds and reconciliation keep the ledger tight, and reports let you see output and input tax at any point in the quarter. Tallium AI supports structured e-invoicing workflows so you are positioned as InvoiceNow (Peppol) adoption widens — please confirm current rules and your own obligations with IRAS or a qualified local tax professional.