Almost no construction project finishes at the price it started at. Scope gets added, deleted, and swapped, and each of those changes has to flow through the pay application correctly — otherwise you're billing against a contract amount nobody agrees on. Change orders are the paperwork that makes a change billable, and the billing rules around them are strict for a reason: the change order line is where pay applications most often get rejected.
This guide covers the one rule that matters most (bill approved change orders only), how a change order reshapes the contract amount and the schedule of values, how the change order summary works, and what to do about the classic trap — performing changed work before the paperwork is signed.
Approved vs pending: only bill approved change orders
A change order is approved when it's signed by everyone the contract requires — typically you and the payer, sometimes the owner or architect above them. Until then it's pending: a proposal, a priced quote, a verbal 'go ahead.' Pending change orders do not belong on a pay application. Adding one inflates the current contract amount past what the payer's own records show, and the mismatch gets the application kicked back — often costing you a full payment cycle on everything else in it.
The reviewer's first check is simple arithmetic: does your current contract amount equal the original contract amount plus the change orders they have signed copies of? If your number includes a CO their file doesn't, the application stalls. Track pending COs in your job costing all you want — keep them off the billing until signed.
How a change order changes the contract amount
The original contract amount never changes — it's the historical baseline. Every approved change order adjusts it up (additive) or down (deductive), and the running result is the current contract amount: original contract amount plus net approved changes. That current figure is the denominator for your percent complete, the ceiling on what you can ever bill, and the number the schedule of values must total to the penny.
New schedule of values lines, or bigger existing lines?
When a change order is approved, its value has to land somewhere on the schedule of values. Two options: enlarge the existing line the work relates to, or add the change order as its own new line. Add new lines. Folding an $8,000 CO into an existing $40,000 line makes the line's history unreadable — six months later nobody can tell how much of the billed amount was base scope versus change, and every percent-complete conversation turns into archaeology. A dedicated line per change order keeps the original schedule of values intact and makes each CO auditable on its own.
- Number CO lines to match the change order documents (CO #1, CO #2...) so a reviewer can pair each line with its signed paperwork instantly.
- One line per change order is the default; split a large CO into a few lines if it contains distinct work that will progress at different rates.
- Enter deductive change orders as negative lines rather than shrinking a base line — same auditability logic in reverse.
- Never retroactively edit base scheduled values. The base lines plus the CO lines should always sum to the current contract amount.
The change order summary
Pay application forms carry a small change order summary: total additions, total deductions, and the net change, split between change orders approved in previous months and those approved this month. It exists so the payer can reconcile your current contract amount at a glance — and see exactly which approvals are newly reflected in this application. Using the example below: an $8,000 additive CO approved in a prior month and a $2,000 deductive CO approved this month.
| Change order summary | Additions | Deductions |
|---|---|---|
| Approved in previous months | $8,000.00 | $0.00 |
| Approved this month | $0.00 | $2,000.00 |
| Totals | $8,000.00 | $2,000.00 |
| Net total of change orders | +$6,000.00 |
A worked example
Base contract $100,000. CO #1 adds a storefront door package for $8,000 (approved, prior month, added as schedule of values line 8). CO #2 deletes a paint scope for a $2,000 credit (approved this month, entered as line 9 at −$2,000). The schedule of values now totals $100,000 + $8,000 − $2,000 = $106,000. On application #3 the project stands at 60% complete overall, with 10% retainage; previous applications earned $45,000 and paid $40,500 after retainage.
- Original contract amount
- $100,000.00
- Net total of change orders (+$8,000 − $2,000)
- $6,000.00
- Current contract amount
- $106,000.00
- Work completed & stored to date (60%)
- $63,600.00
- Retainage held (10%)
- $6,360.00
- Earned to date, less retainage
- $57,240.00
- Less amounts from previous applications
- $40,500.00
- Amount due this application
- $16,740.00
- Remaining balance (including retainage)
- $42,400.00
New earned value this period is $63,600 − $45,000 = $18,600; less the $1,860 of new retainage, that's the $16,740 due. Remaining balance is the $106,000 current contract less the $63,600 earned to date.
Documentation: field directives and T&M tickets
Change order pricing gets challenged less when the underlying record is boring and complete. Two documents do most of the work:
- Field directives (work change directives): written instructions from the payer to proceed with changed work, often before pricing is agreed. A signed directive proves the work was ordered even while the dollar amount is still being negotiated.
- Time-and-material tickets: daily records of labor hours, equipment, and materials on the changed work, signed by the payer's field representative. A stack of signed T&M tickets turns a pricing argument into arithmetic.
- Photos and delivery tickets tied to the changed scope round out the file — cheap to collect in the moment, impossible to reconstruct later.
The classic dispute: changed work without a signed CO
It happens on nearly every project: the field says 'just do it, we'll paper it later,' the work gets done, and the change order never comes — or comes back priced at a fraction of your cost. Now you've financed the work, you can't bill it (it's not in the current contract amount), and your leverage is gone because the work is finished. Most contracts even say changes are only payable with a signed change order, which makes 'we'll paper it later' a promise the contract itself contradicts.
Protect yourself with habits, not heroics: get the direction in writing before starting (a signed field directive, or at minimum an email confirming the instruction and that you consider it a change), run T&M tickets from day one, submit pricing promptly, and chase signatures while the work is still in progress — that's when the payer needs you most. If a CO stays pending for months, raise it in writing and keep it visible on every project meeting agenda. What you should not do is slip it onto the pay application unapproved; that turns your legitimate claim into a billing error.
Frequently asked questions
- Can I bill for a change order that's approved but not yet signed by everyone?
- Not safely. 'Approved' for billing purposes means fully executed per the contract — every required signature. A CO that's verbally blessed or signed by only one party is still pending, and including it invites rejection of the whole application. If approval is genuinely done and only a signature is in transit, ask the payer whether to include it; get the answer in writing.
- How do deductive change orders show up on the pay application?
- As negative amounts: a negative line on the schedule of values, a deduction in the change order summary, and a reduction in the current contract amount. If the deleted scope was partially billed before the deduction, reconcile that line with the payer so earned-to-date never exceeds the reduced line value.
- Do change orders carry the same retainage as base contract work?
- Usually yes — retainage applies to earned value regardless of whether the line came from base scope or a CO, at the contract rate. Some negotiated COs (especially late-project ones) exclude retainage by their own terms. Follow whatever the CO document says; where it's silent, the contract's retainage clause governs.
- What's the difference between a change order and a field directive?
- A field directive is an instruction to proceed with changed work, often issued before the price is agreed; a change order is the signed agreement that changes the contract amount. Directives get the work started and prove it was ordered; only the executed change order makes it billable on a pay application.
- Where does change order work go if I'm billing percent complete?
- Each CO line carries its own scheduled value and its own percent complete, exactly like a base line. Project-level percent complete is total work completed & stored to date divided by the current contract amount — so an approved CO can nudge your overall percentage down even though you billed nothing new, simply because the denominator grew.
