VAT invoices for plumbers: what you must show

When you have to register

VAT registration becomes compulsory once your VAT-taxable turnover goes over £90,000 in any rolling 12-month period, or if you expect to pass it in the next 30 days alone. For a plumber that counts everything you invoice — labour and materials — not the profit you keep.

What a full VAT invoice must show

• A sequential invoice number, unique within its series.
• Your business name, address and VAT registration number.
• The customer's name and address.
• The time of supply (tax point) and the invoice date.
• A description of the plumbing work supplied, per line.
• The VAT-exclusive amount, the VAT rate and the VAT amount per rate.
• The total VAT-exclusive amount and the total VAT payable in sterling.

The rate trap for plumbers

Most repair and maintenance plumbing is standard-rated at 20%. Some work on qualifying residential conversions or on properties empty for two or more years can be reduced-rated at 5% — check the job against HMRC's rules before you invoice, because you cannot casually correct it later.

Worked example at 20%

Net total for the job

£133.50

VAT at 20%

£26.70

Total the customer pays

£160.20

The £26.70 is never your money — you are collecting it for HMRC and paying it over on your next return.

Common questions

Should a plumber charge a call-out fee on the invoice?

Yes — show it as its own line and state what it covers. A call-out that quietly includes the first hour of labour is the single most common cause of a queried plumbing invoice.

Do I have to itemise parts on a plumbing invoice?

There is no legal requirement to break parts down individually, but it is far easier to defend a bill that lists a pump, a valve and pipe than one that says "materials".

What should a plumber's payment terms be?

14 days is the norm for domestic work and 30 days for letting agents or commercial customers. Whatever you pick, put it in writing on the invoice — otherwise the statutory default of 30 days applies.