Standby Generator Service Invoicing App (2026)
Generator work splits into three money shapes: install jobs, annual maintenance plans, and emergency calls when the power is out. ShowTheReceipts ($15/mo) saves the service-kit and labor lines as a catalog, bills annual plans on repeat to a saved card, and lets you invoice an after-hours call at the emergency rate from the driveway.
How we picked
Entry-plan prices as published in 2026, taken from each vendor's own pricing page or a recent third-party summary. Judged on the solo generator technician's workflow — recurring maintenance plans, service-kit parts lines, and after-hours emergency billing — not on dealer parts inventory or multi-branch dispatch.
| Software | Starting price | Best for |
|---|---|---|
| ShowTheReceipts That's us | $15/mo | Solo techs: recurring maintenance plans, saved service-kit lines, emergency-rate invoicing, tax-ready books |
| Invoice2go | $9.99/mo+ | Basic mobile invoicing |
| Joist | Free / $8/mo | Cheapest estimate-and-invoice pair |
| Kickserv Flex | $19/mo | Budget scheduling and invoicing |
| Jobber | $29/mo (Core) | Generator dealers running several service trucks |
Three different businesses on one truck
Generator work doesn’t have one billing shape, it has three, and they need three different treatments:
- Installs — quoted, deposited, invoiced on commissioning
- Annual maintenance — recurring, billed on a card, scheduled off the plan
- Emergency calls — after-hours rate plus trip charge, quoted before you drive
The middle one is the one that pays the bills in a quiet year.
1. ShowTheReceipts — $15/mo
Service-kit lines saved, annual plans billed on repeat, emergency rate available in one tap, and unit records that tell you who’s due.
2. Invoice2go — $9.99/mo+
Simple mobile invoicing without recurring plan handling.
3. Joist — Free / $8/mo
Estimates and invoices at the lowest possible cost.
4. Kickserv Flex — $19/mo
Budget scheduling with invoicing attached.
5. Jobber — $29/mo (Core)
Dispatch for a dealer running several service trucks.
Record the unit, not just the customer
- Make, model, serial
- Install date and hours at last service
- Transfer switch type
- Battery replaced on
That record is what turns “I think we did yours a while back” into a maintenance call you can make with confidence — and a part you can bring the first time.
Storm season is a rate, not a scramble
Set the after-hours number before the outage, not during it. A rate you quote calmly on the phone at 9pm gets paid — a number you invent on the driveway at midnight gets disputed.
Frequently asked questions
How do I bill an annual maintenance plan?
As a recurring invoice on a saved card, with the visit scheduled off the same record. Selling a plan and then invoicing it manually every year is how half of them quietly lapse — the customer didn't cancel, nobody sent the bill.
What should an emergency call cost?
A stated after-hours rate plus a trip charge, quoted on the phone before you drive. During an outage the customer will agree to almost anything; the point of quoting it up front is that they still feel fairly treated a week later, when they're the referral.
Should the service kit be a separate line?
Yes — oil, filters, plugs, and the air filter itemized rather than absorbed into a flat maintenance price. Itemized, the annual visit visibly buys something. Flat, it looks like you charged $300 to listen to an engine run.
How do I keep track of which units are due?
Save each unit — make, model, serial, install date, hours — against the customer, and let the recurring plan drive the schedule. Generator maintenance revenue is entirely a function of remembering, and memory is the part software is actually good at.