How to Charge Materials on a Plumbing Invoice

Plumbers should charge materials on an invoice by listing each important part or consumable with quantity, unit price, markup if used, and GST if registered. Avoid one vague "materials" line for everything. Itemised materials give customers and accounts teams the detail they need to approve the invoice and help plumbers recover the cost of fittings, valves, pipe, hoses and consumables.

This guide covers practical material charging for sole trader plumbers, from small service calls to larger quoted jobs.

Why plumbing materials get missed

Plumbing jobs are full of small parts:

• Washers.
• Flexi hoses.
• Compression fittings.
• Isolation valves.
• Thread seal tape.
• PVC bends.
• Copper pipe.
• Clips, saddles and brackets.
• Mixer taps and cartridges.

The large items usually make it onto the invoice. The small items are the leak. A few dollars per job becomes hundreds per month when you are doing call-outs every day.

Cost plus markup

Many plumbers charge materials at cost plus markup. The markup is not random profit. It covers:

• Time buying or collecting materials.
• Stock carried in the ute.
• Wastage.
• Storage.
• Supplier changes.
• Warranty risk.
• The admin cost of tracking parts.

Common markups vary by business, supplier and job type. The important point is consistency. If your invoice shows materials clearly, the customer can see what was supplied and your business can see whether the job made money.

For broader setup, see materials pricing.

What to itemise

Itemise materials that affect the price or explain the job:

• Fixtures and taps.
• Hot water units.
• Tempering valves.
• Pipe lengths.
• Drainage fittings.
• Valves and hoses.
• Traps and waste parts.
• Equipment charges.
• Consumables when they add up.

You do not need to list every screw if it creates clutter. But do not hide $80 of fittings under "miscellaneous" either.

Example service call

For a toilet repair:

Call-out fee - standard service call.

Labour - diagnose and repair running toilet, 1 hour.

Inlet valve, outlet washer, flexible connector, thread seal.

For a kitchen sink leak:

Labour - repair leaking trap and mixer connection, 1.25 hours.

P-trap, two flexi hoses, isolation valve, washers and sealant.

For a hot water job:

Supply and install hot water unit.

Tempering valve, copper fittings, pipework, disposal fee.

These lines help the customer understand that the invoice is not just time. It includes the parts that made the job complete.

GST on plumbing materials

If you are registered for GST, apply GST correctly to materials and labour. Your invoice should show the subtotal, GST amount and total.

Use the free invoice generator if you need to build a one-off invoice, or check your structure against the free invoice template.

If you are not registered for GST, do not charge GST. You can still itemise materials and show a professional total.

Quote materials before the job

For larger plumbing jobs, quote materials before starting. A quote helps set expectations and gives you a record of what the customer approved.

Use the free quote generator, or build quotes directly from Gmail with the Chrome extension. Once approved, convert the quote to an invoice and add any extra materials used on site.

Voice workflow for plumbers

With voice invoicing, you do not need to type every fitting at the end of the day.

Say:

"Burst pipe repair in ceiling. Two hours labour, three metres 15mm copper, four compression fittings, clips, thread seal, materials markup twenty percent."

SMASH for plumbers turns that into line items while the parts are still in your head. If you use Xero or QuickBooks, Starter and higher plans can sync the invoice to accounting software. See pricing.

Keep a plumbing materials catalog

The fastest material workflow is to save repeat items:

• Common valves.
• Common pipe sizes.
• Standard fittings.
• Washer kits.
• Flexi hoses.
• Equipment charges.
• Disposal fees.
• Standard material markup.

Then each job becomes a short description instead of a blank invoice. You are not trying to remember the price of a fitting at 8pm; the catalog already knows.

Bottom line

Charge plumbing materials clearly, consistently and while the job is fresh. Itemise the parts that matter, apply your markup deliberately, show GST correctly, and stop letting small fittings vanish into unpaid admin.