Invoice templates · Solar
Solar Invoice Template — Free & Fillable
Solar jobs are billed in stages that follow the paperwork, not the calendar: a deposit at signing, a milestone when the array passes city inspection, and the balance when the utility grants permission to operate. This template starts with that last invoice for a real 9.46 kW system — contract lines, both earlier payments credited, and the balance due at PTO.
Make your solar invoice
Prefilled with a sample final milestone (PTO) invoice — every line, the terms and the notes. Swap in your own quantities and rates, add your logo and the customer’s details, and download a clean PDF. Credits like a deposit received go in as a negative rate. No signup, no watermark.
The solar invoices you’ll actually send
Deposit invoice at signing
Small — often 10% — and capped by law in some states (California limits home-improvement down payments to 10% or $1,000, whichever is less). It funds engineering and permitting. Reference the signed agreement, the system size and the contract total, so every later invoice points back to it.
Milestone invoices
Each later invoice repeats the contract, names the milestone reached (“array installed and passed city inspection”), credits every payment so far, and bills the next stage. On financed jobs the lender funds against these same milestones, often after the customer signs off in the lender’s portal, so the wording should match the loan documents.
Service, add-ons and monitoring plans
Service calls, battery add-ons and remove-and-reinstall jobs for a re-roof are ordinary invoices: labor, parts, permit. Monitoring and cleaning plans bill monthly or annually to a card on file.
What goes on a solar invoice
| Line | How it’s billed | Example |
|---|---|---|
| Design and engineering | Flat | $1,650 |
| Permit and interconnection | Flat | $950 |
| Modules | Per panel, wattage stated | $365 per 430 W |
| Inverter | Per unit, kW stated | 7.6 kW $2,650 |
| Battery | Per unit, usable kWh stated | 13.5 kWh $13,900 |
| Array / electrical labor | Crew hours | $95/hr · $125/hr |
| Main panel upgrade | Flat, only if the utility requires it | $3,200 |
| Payments received | Negative lines, one per milestone | Deposit, milestone 1 |
| Referral credit | Negative line | −$500 |
| Monitoring plan | Monthly | $19/mo |
Example prices come from the Brightside Solar demo price book (Tempe, AZ). Your market, crew and suppliers will differ — use them for structure, not as a rate card.
The three invoices on one solar job
The 9.46 kW system from the prefilled invoice, billed across the project. Every invoice shows the same contract and everything paid so far.
| Contract — 9.46 kW DC system at $2.38 per watt | $22,500.00 |
|---|---|
| Invoice 1 · signing — deposit (10%) | $2,250.00 |
| Invoice 2 · installed and passed city inspection (60%) | $13,500.00 |
| Invoice 3 · permission to operate — balance (30%) | $6,750.00 |
Put the system size, the price per watt and the agreement number on every invoice, and change only the milestone line and the payments credited. Anyone — the customer, a lender, a tax preparer — should be able to pick up any one of the three and see exactly where the project stands.
Payment terms, lenders and incentives
Ten days from each milestone is a common term. Tie the final milestone to permission to operate rather than to installation: the customer can’t use the system until the utility signs off, and an invoice that arrives first feels like a bill for something that doesn’t work yet.
On lender-financed jobs, invoice the lender’s milestone exactly as the loan documents describe it, and send the customer a copy marked “for your records — paid by your lender” so nobody pays it twice.
Keep incentives off your price. If a utility rebate is paid to you, credit it as its own line. If a tax credit or other incentive might apply to the customer, don’t present it as a discount: eligibility depends on their situation and on current law, so give them a clear invoice of what they paid and suggest they confirm with a tax professional.
Working out what an overdue balance has accrued? Use the late fee calculator, or see Net 30 and other payment terms explained.
Warranties, production and sales tax
Send the warranty documents with the final invoice: module and inverter manufacturer warranties (often 25 years), the battery (often 10), and your own workmanship and roof-penetration warranty with its start date. Restate that production estimates are modeled, not guaranteed.
Many states exempt residential solar equipment from sales tax, or treat the installation as an improvement to real property where the installer pays tax on materials; others tax it. These rules change — check your state’s current treatment before adding tax.
General information, not legal or tax advice — rules differ by state and change over time.
Frequently asked questions
How do solar installers invoice customers?
In milestones tied to the project: a deposit at signing, a payment when the system is installed and passes inspection, and the balance at permission to operate. Each invoice repeats the contract total and system size, names the milestone, and credits all earlier payments.
What should a solar invoice include?
Your company and license details, the customer and site address, the agreement number, system size in kW DC, equipment by model and wattage, the contract total and price per watt, the milestone being billed, payments already received, the balance due, and the warranty terms.
When is the final payment due on a solar installation?
Usually when the utility grants permission to operate (PTO), sometimes with a short window like 10 days. Billing the final payment at installation, before PTO, is a common source of disputes.
Should a solar invoice show the tax credit?
No. The invoice should show what the customer paid and for what. Whether any tax credit or incentive applies depends on their situation and current law — give them a clear itemized invoice and suggest they confirm eligibility with a tax professional.
Before the invoice: the estimate
Quoting the job first? The solar estimate template is prefilled with a real 8.6 kW rooftop solar system, with deposit terms and the fine print written — approve it, do the work, then bill it here with the same lines. Not sure which document you need? Read estimate vs. invoice, or the full invoice checklist.
More trade invoice templates
Or see all invoice templates.