1. Illinois-specific invoice requirements
- Sales tax line: 6.25% state rate. Most services rendered in Illinois are exempt from sales tax — but materials, parts, and tangible goods are not. Services largely exempt; combined rates up to ~11% in Chicago.
- Late-fee cap: Illinois statute 815 ILCS 205/4 (Interest Act) 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: Illinois requires a signed agreement for any job over $1,000. Reference the contract number on the invoice.
- Right-to-cancel notice: Customers in Illinois get 72-hour cancellation rights on certain home-services contracts. Disclose this in your terms.
2. Welder line items + standard terms
Every welder invoice in Illinois should itemize work clearly. Standard welders use Net 14 terms with a 25% deposit required upfront.
- Labor — billed by hour (~$95 default).
- Filler material — billed by itemized.
- Mobile setup fee — billed by flat (~$150 default).
- Certification surcharge — billed by pct.
3. Welder licensing in Illinois
AWS or state-specific certification required for structural and pressure work. Mobile welders need contractor license in many states for jobs over a threshold.
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. Illinois customers expect digital payment options today — accepting card and ACH typically reduces days-to-paid by 30–50%.
Average invoice
$1,450
State
IL
Net terms
14 days
Deposit
25%
Illinois metro guides
Metro-specific guides include the combined sales-tax rate and local pricing benchmarks.