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Top 5 Construction Billing Methods & Key Considerations

Updated: Jun 25

Effective billing practices are crucial for maintaining a healthy cash flow as a contractor. It also ensures the financial success of your construction projects. With multiple billing methods, navigating the construction billing landscape can be difficult. In this article, we'll explore the top five billing methods, key factors to consider, and expert tips to help you streamline your invoicing process and also improve client communication.

construction billing methods

Top 5 Popular Construction Billing Methods

1. Lump Sum Contract (Fixed-Price Billing):

This method establishes a single, pre-determined price for the entire project scope of work. The contractor develops an estimate which affects all related costs. It will include materials, labor, equipment, overhead, and even a buffer for potential unforeseen circumstances. Once the estimate is finalized and agreed upon by both parties, the lump sum price becomes the fixed cost for the entire project.

Best Used For: Smaller projects with well-defined scopes.


  • Provides cost certainty for clients

  • Encourages contractors to be efficient and control costs

  • Cut down the risk of scope creep or unexpected expenses


  • Have a demand in accurate project scoping and estimation upfront

  • Contractors bear the risk of unforeseen costs or project changes

  • May not be suitable for complex or high-risk projects

2.Time and Materials (T&M) Contract:

Under a time and materials (T&M) contract, payment is based on the actual time spent on the project and the materials used. The contractor typically establishes an hourly rate for labor and a markup percentage on materials. This method is well-suited for projects with a high degree of uncertainty or frequent changes to the project scope.

Best Used For: Projects with uncertain scopes or frequent changes.


  • Contractors are reimbursed for actual costs incurred

  • Suitable for large, complex projects with uncertain scope

  • Encourages transparency and open communication


  • Clients may perceive a lack of cost control incentive for contractors

  • Requires meticulous record-keeping and documentation

  • Can be more time-consuming and complex for billing and accounting

3. Cost-Plus Contract:

A cost-plus contract reimburses the contractor for all project-related costs. This method is often used for complex projects, where the final scope of work may not be fully defined at the outset.

Best Used For: Projects with repetitive tasks, such as road construction or utility installations.


  • Ensure coverage of all costs, incentivizes quality and thoroughness.

  • Allows for flexibility in project scope and changes

  • Reduces the risk of underestimating project costs


  • Lacks cost certainty for clients

  • Requires stringent time invoice tracking and material documentation

  • Easy stuck in client disputes over billable hours or material costs

  • May incentivize contractors to extend project duration

4. Unit Price Contract:

A unit price contract establishes a pre-determined price per unit for specific work items. For example, a unit price contract might specify a price per square foot of flooring installed, per cubic yard of concrete poured, or per linear foot of trench dug. This method will be suitable for some projects with repetitive tasks and clearly defined quantities.

Best Used For: Large, complex projects with variable costs.


  • Provides a clear and straightforward pricing structure

  • Suitable for projects with repetitive or measurable tasks

  • Allows for accurate cost estimation and budgeting


  • Requires accurate estimation of units

  • May not be suitable for complex or highly variable projects

  • Face with disputes over quantity measurements or scope changes

5. Milestone Billing:

Milestone billing in construction releases payment in stages based on the completion of specific project milestones. These milestones stand for key project phases, such as foundation, framing completion, or final inspection. The size and number of milestones can be customized depending on the project's complexity and the agreed-upon payment schedule.

Best Used For: Long-term projects where regular funding is necessary.


  • Helps contractors maintain a steady cash flow

  • Aligns payments with project progress and milestones

  • Allows for better financial planning and resource allocation

  • Reduces the risk of non-payment for completed work


  • Requires clear milestone definitions and progress tracking

  • Potential for disputes over milestone completion or quality

  • May require more administrative overhead for invoicing and progress reporting

  • Clients may face cash flow challenges with larger milestone payments

Key Considerations for Choosing a Construction Billing Method

  • Project Complexity: Highly complex projects with a high degree of uncertainty may benefit from T&M or Cost-Plus methods, while simpler projects might be well-suited for Lump Sum or Unit Price contracts.

  • Risk Tolerance: Lump Sum contracts place more risk on the contractor, while Cost-Plus contracts minimize contractor risk.

  • Cash Flow Needs: Milestone billing and T&M contracts can provide steadier cash flow for contractors, while Lump Sum contracts offer a single, upfront payment for clients.

  • Project Scope and Flexibility: Clearly defined projects with minimal change orders can benefit from Lump Sum or Unit Price contracts, while T&M and Cost-Plus methods offer greater flexibility for unforeseen changes.

Practical Tips for Effective Construction Billing

  • Clear Contracts: Ensure all terms, billing methods, and payment schedules are clearly outlined in the contract to avoid disputes.

  • Regular Communication: Maintain open lines of communication with clients about project progress billing and status.

  • Accurate Record-Keeping: Use efficient billing software to track expenses, labor hours, and materials accurately.

  • Timely Invoicing: Send invoices promptly to avoid cash flow issues.

  • Monitor Progress: Regularly review project milestones and billing status to ensure everything is on track.


Understanding construction billing methods helps you to choose the approach that matches your project's specific needs. Consider consulting with a construction bookkeeper or financial professional to ensure the chosen method is properly documented in your contract for an even more informed decision.

Feeling overwhelmed by managing construction billing methods and invoice management? Our bookkeeping team at Construction Cost Accounting can help! We are an expert in streamlining the billing process with any business size. From contract review and cost tracking to generating invoices and managing cash flow, we take care of all the details so you can focus on building your business. Contact us today to learn how we can simplify your construction billing and boost your bottom line.

Construction Cost Accounting


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