Construction billing determines when and how contractors get paid for completed work. It ties every payment request to a contract, a defined scope, and progress that someone else must verify before funds are released. 

This guide walks through how construction billing works, including the core methods contractors use, the key documents and terminology, and the step-by-step billing process from completed work to final payment. It also covers common challenges, practical tips, and the legal factors that make construction billing more complex than a typical invoice.

What is construction billing?

Construction billing is the process contractors and subcontractors use to invoice for work performed and collect payment throughout a project. It tracks how much work has been completed, ties that progress back to the contract terms, and creates a documented trail that owners, lenders, and project managers can review before releasing funds.

Because construction projects unfold over weeks or months rather than a single transaction, the billing procedure in construction repeats at intervals defined by the contract, rather than occurring once at the point of sale.

Standard business invoicing typically bills for a product or service already delivered in full. Construction billing works differently because payment is often requested for partially completed work, verified against a schedule of values and subject to holdbacks such as retainage. This protects owners from paying for unfinished work while giving contractors the cash flow to keep a project moving.

Key documents and terms in construction billing

Contracts and payment terms

The contract sets the foundation for how billing will work on a project. It defines the billing method, payment schedule, retainage percentage, required documentation, and the timeline for review and approval.

Payment terms commonly range from net 30 to net 90 days. Subcontractor agreements should mirror the payment terms in the prime contract whenever possible to avoid cash-flow gaps between what a general contractor collects and what it owes its subcontractors.

Schedule of values

Schedule of values breaks a project’s total contract price into individual line items, such as sitework, framing, electrical, or finishes, each assigned a dollar value. Contractors bill against this schedule as each portion of work progresses, which gives owners and lenders a clear reference point for evaluating how much of the contract price has actually been earned.

Many contracts require an AIA construction billing format, using forms such as G702 and G703, to present the schedule of values and the corresponding payment application.

Invoices vs. payment applications

Invoices and payment applications are often used interchangeably, though they serve slightly different purposes in construction billing. Standard invoices request payment for goods or services already delivered. Payment applications request payment for construction work completed to date, supported by the schedule of values, updated progress percentages, backup documentation, and any approved change orders.

Payment applications also require a third party, often an architect, owner, or construction manager, to review and certify the amount before funds are released. This typically makes them slower to process than a simple invoice.

Change orders

Change orders document any adjustment to the original scope, schedule, or contract price. When a project deviates from the plans, whether from unforeseen site conditions or owner-requested changes, the added work needs a signed change order before it can be billed. Unbilled extra work is a common way contractors lose money, since it rarely gets paid after the fact.

Retainage vs. an unpaid balance

Retainage is a percentage, typically 5 to 10 percent, that an owner withholds from each payment application until the project reaches substantial completion or the punch list is resolved. Contract terms define retainage in advance, so it functions as a planned holdback rather than a rejected charge.

Unpaid balances describe a different situation: approved work that has not yet been paid, often because of processing delays, disputes, or cash-flow problems on the owner’s side. Contractors who confuse the two risk overestimating how much of their earned revenue is actually available as working capital.

Lien waivers

Lien waivers are signed documents in which a contractor or supplier gives up the right to file a mechanics lien against a property once payment has been received or is about to be received. Owners and lenders often require them before releasing payment, especially on larger commercial projects, to confirm subcontractors and suppliers down the chain have been paid.

Lien waiver requirements and lien rights vary significantly by state. Contractors should confirm the specific rules that apply to their project before signing.

Common construction billing methods

Progress billing

Progress billing invoices the owner based on the percentage of work completed during a given period, typically monthly. Contractors calculate the percentage complete for each line item on the schedule of values, apply that percentage to the contract value, subtract retainage, and submit the resulting payment application.

This method works well for long-term or large-scale projects, such as commercial buildings or infrastructure work, where the schedule spans many months and steady cash flow is essential to keep the project funded.

Fixed-price (lump sum) billing

Fixed-price billing, also called lump sum billing, sets the total contract price before work begins. Contractors bill at agreed intervals or milestones, and the total amount stays the same regardless of actual costs, unless a change order modifies the scope.

This method works best when the scope of work is clearly defined and unlikely to change, such as a residential build with finalized plans. Contractors carry more financial risk under fixed-price billing, since any cost overrun reduces their profit rather than the owner’s budget.

Time and materials billing

Time and materials billing, often shortened to T&M billing, invoices the owner for actual labor hours and material costs, plus an agreed markup for overhead and profit. Contractors typically use this method when the scope of work is not fully defined at the outset, such as emergency repairs or tenant improvements.

Because the final cost depends on hours worked and materials used, T&M billing requires careful time tracking and detailed documentation to support every invoice.

Cost-plus billing

Cost-plus billing charges the owner for the actual cost of labor, materials, and equipment, plus a fee that covers the contractor’s overhead and profit. The fee may be a fixed amount or a percentage of total project costs.

Cost-plus billing suits projects where the scope is difficult to estimate upfront, such as renovations with unknown conditions or custom builds with ongoing design changes. It gives owners visibility into actual costs while reducing the contractor’s financial risk.

Unit-price billing

Unit-price billing charges a set rate for each measured unit of work, such as cost per linear foot, square foot, or cubic yard. Framing or carpentry subcontractors, for example, may apply unit-price billing to charge per linear foot of wall framed, while paving contractors often bill per square yard of asphalt placed.

This method works well for repetitive, measurable tasks like road paving, utility installation, or excavation. It keeps pricing transparent even though the total project cost remains unknown until all units are counted.

Progress billing vs. milestone billing

Progress billing and milestone billing are frequently confused because both tie payment to work completed over time. Progress billing invoices a percentage of the total contract value based on ongoing measured progress, often monthly, regardless of whether a specific phase has finished.

Milestone billing invoices a fixed amount only when a defined phase, such as foundation or framing completion, is finished and approved. Progress billing suits long, continuous projects with steady output, while milestone billing suits projects that break into distinct, verifiable phases.

The construction billing process step by step

Building the schedule of values

Before billing can begin, the contractor and owner agree on a schedule of values that breaks the total contract price into line items tied to specific scopes of work. This document becomes the reference point for every payment application submitted afterward, so its accuracy at the start of the project matters.

Estimators typically build the schedule of values from the original bid, adjusting the level of detail to match what the owner or lender requires for review.

Tracking completed work

Throughout each billing period, project teams track how much of each line item has been completed, often through daily logs, site photos, and progress reports. Accurate tracking prevents overbilling and underbilling, and superintendents typically review percentage-complete figures before they are submitted, since these numbers form the basis of the payment application.

Preparing and submitting the payment application

Once progress is confirmed, the contractor prepares the payment application, applying the completed percentages to the schedule of values, adding any approved change orders, subtracting retainage, and attaching supporting documentation such as receipts, timesheets, and lien waivers from the prior period.

The payment application is then submitted to the party responsible for review, typically an architect, owner representative, or construction manager, according to the deadline set in the contract.

Review, approval, and retainage

The reviewing party checks the payment application against site conditions, contract terms, and documentation before approving it, requesting revisions, or disputing line items. Approved amounts, minus retainage, move forward for payment. Retainage stays with the owner until substantial completion or punch list resolution, then it is released, often as a separate final payment.

Receiving payment and closing out documentation

Once payment is approved and processed, the contractor records it against the project’s accounting records and files supporting documentation for future reference. Thorough recordkeeping protects contractors if a dispute, audit, or lien claim arises later, and it speeds up closeout, since much of the required documentation is already organized.

Tips for efficient construction billing

Start with a clear, detailed contract

Every efficient billing process begins with a contract that spells out payment terms, billing frequency, retainage percentage, and required documentation. Clear contract language prevents confusion later and gives both parties a shared reference point when questions arise about what should be billed and when.

Standardize your construction bill format

Using a consistent construction bill format for every payment application, whether it is a general contractor’s pay application, a carpenter’s bill, or a specialty trade invoice, makes it easier for reviewers to process quickly. Consistency also reduces the chance that a missing line item or unclear description delays approval.

Track change orders separately

Change orders should be logged, priced, and approved separately from the base contract, then added to the schedule of values as their own line items. Keeping them distinct from regular progress billing prevents confusion elsewhere in the construction billing process.

Keep documentation organized from day one

Daily logs, timesheets, material receipts, and photos should be collected as work happens rather than reconstructed later. Organized documentation speeds up payment application review and protects contractors if a billing dispute or audit arises.

Communicate with stakeholders regularly

Regular check-ins with owners, architects, and project managers help surface billing questions before they become disputes. Brief conversations about an unusual line item or a pending change order often resolve issues faster than waiting for a formal rejection.

Follow up on outstanding payment applications

Contractors should track submission and approval dates for every payment application and follow up promptly when a review deadline passes. Consistent follow-up, handled professionally, keeps construction bills moving through approval without straining the relationship with the owner or reviewing party.

Common mistakes in construction billing and how to avoid them

Vague or incomplete construction bills

Construction bills that lack clear line items, dates, or supporting documentation slow down approval and invite questions from reviewers. Contractors can avoid this by matching every payment application to the schedule of values and attaching the backup documentation reviewers expect to see.

Missing or unbilled change orders

Performing extra work without a signed change order is one of the fastest ways to lose money on a project, since unbilled work is difficult to collect after the fact. Contractors should get change orders signed before starting the additional work whenever possible.

Inconsistent billing schedules

Billing irregularly makes cash flow harder to forecast and can catch owners off guard when a large invoice arrives unexpectedly. Setting a consistent billing cadence, whether weekly, biweekly, or monthly, and communicating it clearly from the start of the project helps keep both sides aligned.

Overbilling and underbilling

Overbilling requests payment for more work than has actually been completed, which can trigger disputes or repayment demands once discovered. Underbilling requests payment for less than what has been completed, leaving earned revenue on the table and straining cash flow. Careful percentage-complete tracking against the schedule of values helps prevent both of these common construction billing errors.

Weak documentation and audit trails

Missing or disorganized records make it difficult to defend a payment application if a dispute, audit, or lien claim arises later. Maintaining detailed records of labor, materials, daily logs, and communications throughout the project protects contractors and speeds up approval.

Construction billing software and technology

Construction project billing software helps contractors manage payment applications, track retainage, and maintain documentation without relying entirely on spreadsheets or paper files. Many platforms integrate directly with accounting systems, so invoices, change orders, and payment schedules stay connected to the underlying project data rather than existing as separate documents.

Common features to look for include schedule of values templates, automated retainage calculations, change order tracking, and audit trails that log every revision to a payment application. Some tools focus specifically on construction billing and payment management, while general accounting platforms offer broader bookkeeping features alongside basic invoicing.

The right construction billing software choice typically depends on project complexity, team size, and how tightly billing needs to integrate with existing project management and accounting systems.

Conclusion

Construction billing ties every payment request to verified progress, contract terms, and documented evidence of completed work, which is what separates it from a standard business invoice.

Alliance EDS works with general contractors, subcontractors, and property owners across the Denver, Colorado area on projects where accurate construction billing and honest project management make the difference between a smooth build and a stressful one. Contact Alliance EDS at (720) 484-8181 to discuss your next commercial or residential construction project.

Frequently asked questions (FAQs)