There is a contract on your desk, and the payment article decides everything that happens after the work is done. The choice between an electrical contractor unit price vs time and material contract is not an accounting preference — it decides what you have to be able to prove before anyone pays you.
Unit price bills on quantity installed. Time and material bills on hours worked.
That is a bigger difference than it looks, because the two contracts demand two completely different field records. Sign one, keep the other's paperwork, and the invoice lands with nothing behind it.
When a T&M invoice gets argued, the argument is rarely about the rate. The charge was fair. The explanation was missing.
Unit Price vs Time and Material: The Difference in One Paragraph
A unit price contract sets a fixed price per countable thing installed — per device, per fixture, per foot of MC, per panel — and you get paid for the count. A time and material contract sets an hourly labor rate plus a material markup, and you get paid for the hours you can account for.
The count is verifiable by both parties. Anyone can walk the second floor and count 62 devices.
Hours leave nothing on the building. There is nothing to walk up to and count, so the only record of them is the one you made. That is the entire practical difference, and it is where the risk moves.
| Unit price contract | Time and material contract |
|---|
| You get paid for | Quantity installed | Hours worked, plus material |
| The number on the invoice | Count × unit price | Hours × rate, plus material at cost plus markup |
| Risk you carry | Productivity — your real hours per unit against the hours baked into the price | Administrative — proving the hours, and collecting on them |
| What the customer verifies | The count, against the drawings and the walls | Your paperwork, and nothing else |
| What kills the invoice | A disputed quantity, or work with no matching unit | An hours total nobody can reconstruct |
| Field record it demands | Units in place, by location, by day | Hours by person by day, and what those hours went to |
Which Contract Should You Sign for This Job?
If the scope is drawn, countable and repetitive, take unit price. If you will be working around existing conditions, demolition, or anything you can only find out by opening a wall, take time and material.
That rule holds up better than any list of pros and cons, because it turns on one thing: whether the quantity is knowable before you start.
| The work | Contract that fits | Why |
|---|
| Multifamily rough-in, 40 identical units | Unit price | Countable, repetitive, drawings issued, spec locked |
| Fixture package on a new build | Unit price | The fixture schedule gives you the count before you bid |
| Site lighting, pole bases and feeders | Unit price | Per base, per foot of trench, all on the civil drawings |
| Data drops in an open-ceiling office | Unit price | Per drop, conditions visible from the floor |
| Occupied-building retrofit | T&M | You cannot count what is above the grid until you are on the lift |
| Troubleshooting a nuisance trip | T&M | The scope is the diagnosis; there is no unit to price |
| Service calls | T&M or flat rate | Unknown until you open the panel |
| Demo and removal of abandoned wiring | T&M | Quantity unknown, and routinely understated on the drawings, because nobody surveyed what is up there |
| GC-directed extras mid-job | T&M | By definition not in the schedule you signed |
If the GC hands you a unit price schedule for work that belongs in the right-hand column, you are being asked to price a quantity nobody has counted. Say so in writing before you sign, not after the first change.
The Same Tenant Improvement, Priced Both Ways
Here is one example scope run through both contracts with every input visible. These are example numbers, not benchmarks — replace each input with yours.
Example scope: second-floor tenant improvement, new work, drawings issued and spec fixed. 62 devices rough and trim, 1,400 ft of 12/2 MC, one 42-circuit panel changeout. Example billed labor rate buildup| Input | Example value |
|---|
| Journeyman base wage | $38.00/hr |
| Payroll burden at 32% of wage | $12.16/hr |
| Truck, tools, shop and overhead allocation | $18.00/hr |
| Cost subtotal | $68.16/hr |
| Profit at 18% of cost | $12.27/hr |
| Billed labor rate ($80.43, billed at $80.00) | $80.00/hr |
| Line item | Qty | Hrs/unit | Labor/unit | Material/unit | Unit price | Extended |
|---|
| Device, rough and trim | 62 ea | 0.55 | $44.00 | $10.93 | $55.00 | $3,410.00 |
| 12/2 MC, installed | 1,400 ft | 0.022 | $1.76 | $1.32 | $3.10 | $4,340.00 |
| Panel changeout, 42 ckt | 1 ea | 26.0 | $2,080.00 | $1,667.50 | $3,750.00 | $3,750.00 |
| Contract total | $11,500.00 | |||||
| Labor hours priced into that total (62 × 0.55, plus 1,400 × 0.022, plus 26.0) | 90.9 hrs | |||||
The 0.022 hrs/ft assumes open ceiling, cable dropped from tray, no fishing and no fire-caulk — published labor unit books run two to three times that for the same cable in finished or obstructed space. Use your own number, and write down the conditions it assumes.
The same scope billed as T&M, with an example actual of 98.5 hours because the existing ceiling grid had to come down to clear the corridor run:| Line | Example arithmetic | Amount |
|---|
| Labor | 98.5 hrs × $80.00/hr | $7,880.00 |
| Material | $3,649.00 at cost, plus 15% | $4,196.35 |
| Invoice total | $12,076.35 |
The gap is the whole lesson. You priced 90.9 hours and burned 98.5.
Under unit price those 7.6 hours are yours — about $608 at the $80/hr example rate. Under T&M they are billed, and the invoice comes to $12,076.35 instead of $11,500.00.
Unit price does not make you more money or less money. It moves who absorbs the hours nobody predicted.
The Hybrid You Actually End Up Signing
Very few electrical jobs of any size are purely one or the other. What gets signed is a unit price base with T&M for extras and unforeseen conditions.
That structure only protects you if the trigger is written down before the first change. Here is wording you can adapt:
Work not shown on the unit price schedule — including demolition, removal or relocation of existing electrical, troubleshooting of existing circuits, work performed out of the sequence shown in the current schedule, and standby time caused by others — is performed on a time and material basis at $\_\_/hr journeyman and $\_\_/hr apprentice, material at cost plus \_\_%, upon written authorization from the General Contractor's superintendent obtained before the work begins. Where prior written authorization is not practical, verbal authorization will be confirmed by a T&M ticket presented for signature at the end of the shift on which the work was performed.
Two details in there do the work. It names the categories that always come up, so nobody argues later about whether demo was "included."
And it puts a signature at the end of the same shift, while the superintendent still remembers the ceiling being open.
Keep the two sets of paper separate from day one. Unit price quantities on one sheet, T&M hours on another, never blended into one running total — because the moment they blend, the GC gets to argue your T&M hours were already inside the unit price.
What Each Contract Makes You Prove
Unit price is proven by a count. T&M is proven by a description. Neither one is proven by an hours total on its own.
| Backup element | Unit price | Time and material |
|---|
| Authorization before the work | The signed schedule of values | Required, per ticket, per occurrence |
| Daily field record | Units set, by location and date | Hours by worker by day, and what they went to |
| Material | Included in the unit price | Invoices or packing slips, with the markup shown |
| Spec confirmation | Device or fixture type matching what was priced | Not usually at issue |
| Signature | On the quantity agreed at each pay application | On each ticket, ideally the same day |
| Quantity variation terms | Essential — the over/under-run threshold | Not applicable |
| Common failure | Work with no matching unit, billed at nothing | Hours with no description, discounted at the table |
This is where the two contracts stop being a legal question and become a field question. The record your crew makes is the explanation your customer reads, and each contract needs a different sentence from them.
A record that reads 8.77 hrs proves nothing under either one. It survives payroll and loses every argument after that.
Tue — 2nd flr east: 18 devices set and trimmed, rms 214–221. 240 ft MC pulled, corridor C2 to C4.
Now the pay application has a running count with a location behind every number, and the superintendent can verify it by walking the floor.
Under T&M, the daily note says what the hours went to:Thu 7:02a–3:48p — pulled and terminated circuits 12–18, second-floor east wing. 1.5 hrs removing abandoned MC above the grid to clear the run.
That second sentence is a T&M extra sitting inside a unit price job, caught on the day it happened. It becomes a ticket instead of a write-off.
Neither note takes more than fifteen seconds to write. The method is asking for one line at the end of the shift — what got done and where — instead of asking for a total.
If you want the paperwork already laid out, the free T&M Billing Backup Kit has the work authorization form, the labor backup sheet, the daily field report and the change-order log. Print them and run either contract type on paper.
The Units That Are Not on the Schedule
This is where unit price jobs actually go wrong, and it is almost never the units themselves.
It is demo nobody counted, rework caused by another trade, an owner-directed spec change, standby time when the ceiling is not ready, or a fixture that changed after you bought the first batch. None of those have a line on the schedule.
Hours spent on them are free unless you capture them as T&M extras. Four steps, all of them free:
- Stop and name it. The moment work does not match a unit on the schedule, it is an extra — not "we'll sort it out at the end."
- Get authorization before the hours are spent. The trigger clause above, or a text message you keep. A text with a date beats a memory every time.
- Keep the extra's hours on a separate ticket, with the description, from the first hour. Do not fold them into the day's job total.
- Get the ticket signed at the end of that shift. An unsigned ticket found three weeks later is a negotiation. A signed ticket is an invoice.
How You Find Out Whether Your Unit Price Was Profitable
A unit price is only profitable if your real hours per unit match the hours you baked into it. The only way to find out is to have hours recorded against the scope those units belong to.
Run this after the job closes, with your own numbers:
| Example check | Value |
|---|
| Devices installed | 62 |
| Hours priced (62 × 0.55) | 34.1 hrs |
| Hours actually charged to device rough and trim | 41.2 hrs |
| Real hours per device (41.2 ÷ 62) | 0.66 hrs |
| Difference (7.1 hrs × $80.00/hr example rate) | $568.00, or $9.16 per device |
Bid the next one at 0.55 hrs per device and, on these example inputs (7.1 hrs over, 62 devices, $80.00/hr example rate), the same $9.16-per-device gap repeats on any job that runs like this one.
Labor unit books are a reasonable starting point — NECA's Manual of Labor Units is the standard reference most electrical estimators work from — but they are national averages with condition factors, not your crew on that building. Your own history is the correction, and you only have a history if the hours were written down against something narrower than "the job."
You do not need software for this. A column on the daily sheet for what the hours went to, totaled at close-out, gets you there.
A time app can keep the hours and the description together for you — FieldTimesheet captures a note at clock-out with each entry, and pushes finished hours to QuickBooks Online when an admin clicks Sync to QuickBooks. It records hours against the job, not against a unit type, so that split still comes off your daily sheet. It will not count installed devices for you either — it stores hours and the note attached to them. The unit tally stays a field job, on the same sheet, in the same handwriting.
Prevailing Wage and Public Work
On public jobs with certified payroll you are already producing per-worker daily hours whether you want to or not. That is a T&M-grade record, required by law, sitting in your payroll file.
Add the one-line description of what the hours went to and the same record does double duty: certified payroll on Friday, invoice backup when the extra gets disputed in March.
Prevailing wage also changes the rate buildup above. Rerun the base wage and fringe inputs at the determination rate before you accept a unit price schedule that was written for private work.
What to Do Monday Morning
All of this works with the contract you already signed and a clipboard.
- Read the payment article. Find whether it says you get paid on quantity or on hours. That one sentence tells you which record you owe.
- Set up the matching daily sheet. Unit price: units set, location, date. T&M: worker, in and out, and one line on what the hours went to.
- Ask the crew for one sentence, not a report. "What did you get done, and where," at the end of the shift. Nobody writes a paragraph; everybody can write a line.
- Find the extras already in flight. Anything running now with no unit on the schedule gets its own ticket today, not at close-out.
- Write the T&M trigger clause into the next contract you sign, with your rates filled in and a named person who can authorize.
Frequently Asked Questions
What is the difference between a unit price contract and a time and materials contract for electrical work?A unit price contract pays a fixed amount per item installed — per device, per fixture, per foot of conduit — so the invoice is settled by counting. A T&M contract pays for hours worked plus material with a markup, so the invoice is settled by whether your record explains the hours.
Can an electrical contractor use unit pricing and T&M on the same job?Yes, and it is the common structure on commercial work. A unit price base covers the drawn, countable scope, and a clause sends demolition, unforeseen conditions and GC-directed extras to T&M on written authorization.
Which is riskier for the electrical contractor, unit price or time and materials?They carry different risks. Unit price puts productivity risk on you — if real hours per unit run over what you priced, you absorb the difference. T&M removes that risk and replaces it with collection risk, because you are only paid for hours the customer accepts.
How do you set a unit price for electrical work?Take your labor hours per unit, multiply by your loaded billed rate, add material at cost plus your markup, then round. Hours per unit is the number that decides whether the price works, and the honest source for it is your own completed jobs, checked against a labor unit reference such as NECA's manual.
What documentation does a customer need before they will approve a T&M invoice?Authorization obtained before the work started, hours by worker by day, a plain description of what those hours went to, material invoices with the markup disclosed, and a signature from someone with authority — ideally on the day of the work. The description is the part most invoices are missing.
What happens when electrical work falls outside the unit price line items?It gets billed as a T&M extra, or it gets done for free. There is no third option. Name it as out of scope the day it comes up, get authorization before the hours are spent, and keep those hours on a separate ticket from the unit price work.
How do you know whether your unit price is actually profitable?Compare the hours you priced into each unit against the hours actually recorded on that scope when the job closed. If you priced 0.55 hours per device and the job ran 0.66, you are short 0.11 hours per device on every job you bid the same way.
Can you use unit pricing on prevailing wage or public electrical jobs?Yes, but rebuild the rate first. The determination wage and fringe rates change your loaded cost per hour, so a unit price written for private work will be underpriced on public work by that difference. Certified payroll also means the per-worker daily hours record already exists — use it as your backup when an extra is challenged.