Invoice Koi

Invoicing for HVAC engineers

Half the year is planned maintenance and half of it is somebody with no cooling in August. The planned half should invoice itself and mostly does not; the unplanned half is written up late, from memory, after a long day on a roof.

An illustration of manifold gauges, a pleated filter, a length of flexible duct and a thermostat dial, with a koi swimming among them.
01On the document

What HVAC engineers
put on an invoice.

These go in your price book once, with your own prices against them. After that a line is one tap: the item, the description, the unit and the price fill themselves, and the totals resolve underneath.

LineUnit
HVAC labourhrs
Service visit, planned maintenanceeach
Call-out and diagnosiseach
Refrigerantkg
Filters and beltseach
Unit supply and installeach

Prices are yours. Invoice Koi ships a handful of round placeholder lines to start from and never fills your book with figures you did not set.

A job, grouped Subtotals per section
DIAGNOSIS
Call-out and diagnosis£120
Subtotal£120
REPAIR
HVAC labour£420
Refrigerant£180
Condenser fan motor£340
Subtotal£940
SERVICE
Filters and belts£95
Subtotal£95
Total£1,155
Grouped line items are free, on all nine templates.
A photograph of an HVAC engineer on a flat roof beside a condenser unit, phone in one hand.
Price book
HVAC labourhrs
Service visit, planned maintenanceeach
Call-out and diagnosiseach
One tap puts the line on the invoice.
This job, grouped
DIAGNOSIS£120
REPAIR£940
SERVICE£95
Total£1,155
No signal needed. It is written here.
02Why HVAC engineers use it

Three things that
save the evening.

Maintenance visits on the schedule

Put a site on a weekly, fortnightly or monthly visit and the jobs calendar carries the series. The invoice for each one starts from what you actually did.

Service contracts that repeat

A recurring invoice drafts itself on your cadence, quarterly or yearly, so a contract does not depend on anybody remembering the anniversary.

What each site cost you, by quarter

Income, tax and hours by period, as a CSV, a spreadsheet or a PDF. The reports answer "was that contract worth it" without a spreadsheet of your own.

03 · Questions

Asked by HVAC engineers.

Can I invoice a maintenance contract automatically?

A recurring invoice drafts on the cadence you set, weekly through to yearly. You look at it and send it; nothing is sent to a customer without you pressing send.

Can I bill refrigerant by weight?

Yes. A price-book line carries its own unit, so refrigerant bills per kilogram, labour per hour and a unit install per each, on the same document.

Does it track time on site?

Yes. Track hours against a client and turn them into a line on the invoice, rather than typing them in twice.

Other trades