1. Hawaii-specific invoice requirements
- Sales tax line: 4.00% state rate. Services billed to HI customers must include sales tax. GET (general excise tax) 4%; applies broadly to services. Honolulu adds 0.5%.
- Late-fee cap: Hawaii statute Haw. Rev. Stat. §478-2 caps interest on unpaid invoices at 1.5% per month. Spell out the rate in writing on every invoice and in your contract — courts won't enforce undisclosed fees.
- Written contract required: Hawaii requires a signed agreement for any job over $1,000. Reference the contract number on the invoice.
- Right-to-cancel notice: Customers in Hawaii get 72-hour cancellation rights on certain home-services contracts. Disclose this in your terms.
2. Civil / Mechanical / Electrical Engineer (PE) line items + standard terms
Every civil / mechanical / electrical engineer (pe) invoice in Hawaii should itemize work clearly. Standard civil / mechanical / electrical engineer (pe)s use Net 30 terms with a 25% deposit required upfront.
- Project fee — billed by flat.
- Hourly engineering — billed by hour (~$175 default).
- PE stamp & sealing — billed by flat.
- Site visit — billed by flat.
3. Civil / Mechanical / Electrical Engineer (PE) licensing in Hawaii
PE license required to stamp drawings or sign engineering opinions. Discipline-specific rules apply.
4. Send and follow up
Send the invoice the same day work completes. Use software that records open events and offers a one-click online payment so you don't need to chase a check by mail. Hawaii customers expect digital payment options today — accepting card and ACH typically reduces days-to-paid by 30–50%.
Average invoice
$6,500
State
HI
Net terms
30 days
Deposit
25%
Hawaii metro guides
Metro-specific guides include the combined sales-tax rate and local pricing benchmarks.