"We did the extra work, but they won't pay for it."
That sentence has cost subcontractors millions. The work was real. The hours were spent. But without proper documentation, you're asking someone to trust your memory—and memory doesn't pay invoices.
T&M (time and material) work requires documentation discipline. Here's exactly what to track and how.
The T&M Documentation Framework
Every T&M claim needs four elements:
- Authorization – Proof the work was directed
- Labor records – Who worked, how long, doing what
- Material records – What was used, what it cost
- Verification – Signatures confirming the work occurred
Missing any element weakens your claim. Missing multiple elements often means no payment.
Pre-Work: Getting Authorization
Written Directive
Before starting T&M work, get written authorization:
Minimum acceptable:
- Email directing the work
- Text message acknowledged
- Field directive on GC letterhead
Better:
- Formal change order request
- T&M authorization form with scope description
- Reference to contract T&M rates
What Authorization Should Include
- Description of work requested
- Reason it's extra (owner change, unforeseen condition, etc.)
- Acknowledgment that T&M rates apply
- Authorization signature and date
When You Can't Get Pre-Authorization
Sometimes you must act quickly. Document:
- Who verbally directed the work
- Date, time, and circumstances
- Why immediate action was necessary
- Follow up in writing immediately after
Email: "Per your direction today at 2pm, we proceeded with [work] on a T&M basis due to [reason]. Please confirm."
Daily Labor Documentation
The T&M Time Sheet
Create or use a form that captures:
| Field | Why It Matters |
|---|---|
| Date | Establishes when work occurred |
| Worker names | Shows who was there |
| Hours per worker | What you're billing |
| Task description | What work was performed |
| Location | Where in the building |
| Conditions | Anything affecting productivity |
| Authorization reference | Links to the directive |
| Signature lines | GC/owner acknowledgment |
Level of Detail
Not enough: "8 hours – change order work"
Minimum: "8 hours – Relocated 4 sprinkler heads per ASI #12, Level 2 west corridor"
Better: "8 hours – Relocated 4 sprinkler heads per ASI #12 from original locations shown on drawing FP-201 to new locations per revised ceiling plan. Required drain-down, cutting existing pipe, rerouting branches, and re-pressurizing system. Work performed in occupied corridor requiring after-hours access."
Getting Signatures
The signature requirement is where most T&M documentation fails.
Daily: Get the GC field superintendent to sign each day's time sheet Alternative: If daily isn't possible, weekly at minimum Dispute protection: If they refuse to sign, document the refusal and send written notice
"Our T&M time sheet for [date] was presented to [name] at [time] for signature. Signature was declined. This notice serves as our record of hours worked."
Material Documentation
What to Track
For every material purchase:
- Item description and quantity
- Where it was used (link to T&M work)
- Purchase cost (invoice/receipt)
- Markup applied per contract
Supporting Documents
Keep copies of:
- Supplier invoices
- Delivery tickets
- Credit card receipts if applicable
- Price quotes for special-order items
Markup Clarity
Your contract specifies T&M markup rates. Apply them clearly:
| Item | Cost | Markup | Billed |
|---|---|---|---|
| 2" copper pipe (50 LF) | $325.00 | 15% | $373.75 |
| Fittings | $87.50 | 15% | $100.63 |
| Material total | $412.50 | $474.38 |
Transparency prevents disputes.
Equipment Documentation
If T&M rates include equipment:
- Equipment type and size
- Hours or days on site
- Rate applied
- What work it supported
Log equipment daily, even if rates are included in labor.
Submitting T&M Documentation
Timing Is Critical
Submit T&M backup:
- Daily: For ongoing work, submit daily time sheets daily
- Weekly: Minimum acceptable frequency
- With pay apps: Include T&M summary with monthly billing
Never: Wait until project end to submit all T&M documentation
Package Organization
Each T&M submission should include:
- Cover sheet with summary
- Authorization document
- Time sheets (signed)
- Material documentation
- Equipment logs if applicable
- Photographs if relevant
Follow-Up
Track the status of T&M submissions:
- Date submitted
- Response received
- Issues raised
- Resolution status
Unanswered submissions should trigger follow-up within 7-14 days.
Common T&M Documentation Failures
Failure 1: No Pre-Authorization
Starting T&M work without direction documented. Even if someone told you to do it, without written evidence you're relying on their memory and honesty.
Failure 2: Unsigned Time Sheets
Detailed time sheets mean nothing if the GC claims they never happened. Signatures are your proof.
Failure 3: Vague Descriptions
"Extra electrical work – 24 hours" doesn't tell anyone what was done or why it was extra. Be specific.
Failure 4: Missing Material Backup
Claiming $5,000 in materials without invoices. Even if you spent it, you can't prove it.
Failure 5: Late Submissions
Submitting T&M documentation months later. Memories fade, people leave, and urgency disappears.
Digital Documentation Tools
Modern tools make T&M documentation easier:
Photo documentation:
- Timestamp photos of work in progress
- Before/after conditions
- Location tags
Digital signatures:
- Apps that capture signatures on tablets
- Email confirmations with timestamps
- Project management system acknowledgments
Templates:
- Standardized T&M forms
- Pre-populated worker information
- Automatic calculations
Using AI for T&M Documentation
AI can help organize and summarize T&M documentation:
I have T&M time sheets for 3 weeks of extra work.
Create a summary that includes:
- Total hours by worker
- Tasks performed with hours allocated
- Total labor cost at $85/hour
- Link to authorization (CCD #14)
Format for submission to the GC.
T&M Documentation Checklist
Before submitting any T&M claim:
- Written authorization on file
- Daily time sheets complete
- Time sheets signed by GC representative
- Work descriptions are specific and clear
- Material invoices attached
- Markup rates match contract
- Equipment logged if applicable
- Photos support the work performed
- Submitted within contract timeframes
What's Next
Good T&M documentation is defensive. But the real skill is recognizing extra work before you perform it—and getting authorization before you're committed. Next, learn to identify change order situations early.
TL;DR
- T&M requires four elements: authorization, labor records, material records, verification
- Get written authorization before starting—even a confirmed email counts
- Time sheets need signatures—unsigned sheets invite disputes
- Be specific in descriptions—vague claims get rejected
- Submit documentation daily or weekly—never wait until project end
- Keep material invoices and apply markup transparently
- Track submission status and follow up on unresolved items