Time and materials pricing bills the client for your labor by the hour plus the materials you buy, either at cost or with an agreed markup. It fits jobs where the scope is unclear, like troubleshooting or repairs with surprises behind the wall. A good agreement fixes your hourly rates and adds a ceiling or an approval step before costs run past it.
TL;DR:
- Set labor rates by category, specify whether materials are billed at cost or with an agreed markup, and require written approval above the ceiling.
- Log daily start and stop times, describe the work, save receipts, and photograph progress; record drive time only if the agreement bills for it.
- Use T&M for diagnostics, emergencies, and hidden conditions; reserve fixed pricing for repeatable work, or price discovery first before shifting to T&M.
- Send invoices weekly or at milestones, with dates, hours, rates, work descriptions, and material receipts, and alert clients before charges approach the written ceiling.
Table of Contents
- What goes into a time and materials contract
- How rates, time tracking, and materials billing work day to day
- When time and materials beats fixed price, and when it doesn't
- Billing and invoicing steps that keep T&M payments moving
- Contract terms every T&M agreement should include
- How to set your hourly rate: a five-step calculator
- Copyable clauses and invoice fields
- What we learned about fewer disputes and faster pay
- Run your T&M jobs from one simple tool
- FAQ
- Sources
What goes into a time and materials contract
A T&M contract covers labor categories, materials, and a ceiling. Labor categories are the types of work you bill, such as journeyman electrician or helper. Each gets its own fixed hourly rate. Federal acquisition rules say those rates should be fully burdened, meaning they include wages, overhead, general and administrative costs, and profit.
Materials are the parts and supplies bought for that specific job: a water heater, a run of wire, a bag of fertilizer. Under the federal payment clause, materials are reimbursed when documented, so keep receipts. You can bill them at cost or add an agreed markup.
The ceiling is a cap on total charges. Without client approval, you stop or ask before going past it. It protects the client from runaway bills and protects you from arguments.
T&M is different from a fixed-price contract, where one number covers the whole job, and from a labor-hour contract, which bills hours only with no materials.
How rates, time tracking, and materials billing work day to day
Start with the rate. Your hourly number has to cover more than your paycheck:
- Payroll taxes and self-employment taxes
- Liability insurance and bonding
- Tools, vehicle costs, and fuel
- Phone, software, and office time
- Profit you keep after everything else
For materials, you have two options. Pass-through means you bill exactly what you paid. Cost-plus adds a percentage for sourcing, hauling, warranty risk, and carrying the cost until the client pays. Our guide on materials markup tiers walks through how to pick a percentage.
Time capture is where most disputes start or die. Use a simple daily log: start time, stop time, and a one-line note on what you did. Snap a photo of the work before and after. Write drive time down if your agreement bills for it.
On the quote and invoice, keep labor and materials on separate lines so the client sees hours times rate, then parts.
Pro Tip: Photograph every receipt before it fades or gets lost in the truck.
When time and materials beats fixed price, and when it doesn't
Choose T&M when you can't see the whole job yet. A plumber chasing a slow leak, an HVAC tech diagnosing a unit that cycles off, or an electrician opening an old panel all face unknowns. Federal guidance says T&M suits work where the extent or duration can't be estimated accurately. Emergency calls fall in the same bucket.
Choose fixed price when the scope is clear and repeatable. Swapping a standard water heater, installing a ceiling fan, or mowing a set property every week all have predictable hours. A fixed number is easier for the client to say yes to.
Some clients push back on open-ended billing. A hybrid can calm them: charge a fixed price for a discovery visit that defines the job, then move to T&M for the unpredictable part. The Engineering Institute of Technology describes this approach as a way to win work and build trust.
Before proposing T&M, run this checklist in your head: Can I describe the finished job? Do I know the hours within reason? Has the client seen my rates? Is a ceiling in writing? If the answer to the first two is no, T&M is probably your model.
- Favors T&M: diagnostics, repairs, emergencies, remodels with hidden conditions
- Favors fixed price: standard installs, recurring cleaning or lawn routes, small defined punch lists
Billing and invoicing steps that keep T&M payments moving
Good T&M invoicing is mostly good documentation. Follow these steps on every job:
- Send progress invoices on a set schedule, weekly or at milestones, instead of one big bill at the end.
- List each line item with date, hours, rate, and a short description of the work.
- Attach or link receipts and photos for big materials like equipment or fixtures.
- Set payment terms and any deposit up front, and say when you will warn the client as costs near the ceiling.
- Settle questions fast, starting with the log and photos, not with opinions.
A deposit is a payment before work starts, usually to cover materials. An invoice is a request for payment for work done. Keep them labeled separately so nobody confuses them.
When a client questions a charge, try a short script: "Here is the log for that day and the photo of the part. Which line looks off to you?" Small disputes usually end right there. Industry guidance from DocuSign also stresses time capture and clear client communication as the way to avoid billing fights. Our progress invoicing checklist lists the fields to include.
Pro Tip: Send a heads-up message as costs approach the ceiling, before the client gets surprised.
Contract terms every T&M agreement should include
Put these clauses in writing, in plain words:
- Labor rates: Name each labor category and its exact hourly rate. State what the rate covers, such as tools, benefits, and travel.
- Ceiling: Set a not-to-exceed amount. Require written notice and client approval before you go above it.
- Materials rules: Say what counts as direct materials, whether markup applies and at what percent, and that receipts back every charge.
- Material price changes: Prices can swing fast. The Associated General Contractors of America reported a big jump in material prices over a single year, so consider a clause that lets you adjust or confirm pricing on long jobs.
- Change orders: Write a simple path: you estimate the extra work, the client signs off, and you issue a revised invoice or ceiling.
- Payment terms: Due dates, accepted payment methods, and any late fee.
A clean quote helps here too. Our estimate mistakes checklist catches the gaps that cause trouble later.
How to set your hourly rate: a five-step calculator
Here is a quick formula for a solo electrician. Choose a target take-home income, then add payroll taxes, insurance, and yearly overhead for tools, a truck, software, and a phone. Estimate your billable hours after driving, quoting, and paperwork. Divide the total costs and income target by your estimated billable hours to get a starting hourly rate.
Add profit on top if your income target did not include it. Then consider surcharges: a premium for emergency calls, weekends, or specialty skills like gas line work. Many pros set these as a flat percentage and list them in the contract so nobody is surprised.
Copyable clauses and invoice fields
Paste these into your documents and adjust the details:
- Quote line: "This job is billed by time and materials: hours at $80 per hour plus parts at cost plus 15%. We will not exceed $2,500 without your written approval."
- Progress invoice fields: billing period, date and hours times rate for each entry, materials with receipt attached, subtotal, taxes, total due, and remaining balance under the ceiling.
- Change-order snippet: "Added work: [describe]. Estimated hours: [number]. New ceiling: [amount]. Client signature and date: ______."
For full layouts, see our contractor quote template and handyman invoicing steps.
What we learned about fewer disputes and faster pay
In our experience, most billing fights come from missing paperwork, not bad intent. Write down hours the same day, send invoices while the job is fresh, and keep quote, invoice, and review request in one flow. Cutting admin time often speeds payment more than raising your rate does, and Quotewren is built to turn a quote into an invoice and then trigger an automated review request.
— jaras
Run your T&M jobs from one simple tool
Quotewren offers a Free plan, a Quotewren plan at $19 per month, and Quotewren Crew at $39 per month. Try Quotewren today.
FAQ
What is the definition of a time and materials contract?
A time and materials contract bills the client for labor hours at fixed hourly rates plus the cost of materials. Under federal payment rules, rates are multiplied by direct labor hours and documented materials are added. Most also include a ceiling price.
Should I pay a contractor 50% upfront?
A deposit should fit the job and cover agreed upfront costs, such as materials. The rest can be paid as work progresses. Check your local rules and agree on a payment schedule in writing.
How much should I pay a contractor per hour?
Rates vary by trade, experience, and local costs. A fair rate covers the contractor's wages, insurance, tools, and overhead, not just pay. Ask for the rate in writing and for what it includes.
How do I handle a disagreement over a T&M bill?
Start with the documents: the time log, receipts, and photos. Walk the client through the questioned line, fix any real error, and agree on the corrected total in writing.
Sources
- Acquisition
- What is Better – A Fixed Price or Time & Material Contract - Engineering Institute of Technology :Engineering Institute of Technology
- Agc