An HVAC invoice should include your company name, license number, and contact info; the customer's name and service address; a unique invoice number; the service date; itemized parts (refrigerant, capacitors, filters) with quantities and unit prices; labor hours and rate; subtotal, tax, and total due; and your warranty terms.

Yes. A diagnostic or service call fee ($75–$150) covers travel and inspection time. Many contractors credit this fee toward the repair cost if the customer proceeds. List it as a separate line item so the customer can see exactly what they're paying for.

List each part as its own line item — refrigerant by the pound, capacitors individually, filters by size. Then add a separate labor row with hours worked and your hourly rate. This makes warranties easier to track and gives customers full transparency.

Sales tax rules vary by state. Most states tax HVAC parts and equipment; some also tax installation labor. Use the Tax % field in the toolbar above to apply your local rate. Always consult your accountant for state-specific rules.

For warranty work, create a $0.00 invoice documenting all work performed and referencing the original invoice number. Note the warranty coverage period in the Terms section. This creates a paper trail for both parties and protects you from future disputes.