An estimate is used before work begins to show the expected cost of a job, while an invoice is sent later to request payment. This guide explains when to use each one, how they fit into the workflow, and how an approved estimate can later be turned into an invoice.
An invoice and an estimate may include similar details, but they are used at different stages of a job. An estimate is sent before the work begins to show the expected cost based on the scope, materials, labor, or services involved. An invoice is sent after the work is completed, or at a billing milestone, to request payment.
Both documents help keep the job organized, but they serve different purposes. An estimate helps the client review the expected price before approving the work. An invoice tells the client what is now due.
An estimate is a pricing document sent before the client agrees to the job or before the work starts. It gives the client an approximate cost based on what is currently known.
For example, a contractor may send an estimate for a kitchen repair project showing labor, materials, and an expected total of $2,500. The final amount may change if the scope changes, but the estimate helps the client decide whether to move forward.
Estimates are useful because they create a pricing baseline without acting as a final payment request. They help clients compare options, approve work, and understand what the job is likely to cost.
Common examples of when to use an estimate include:
If you need help getting started with estimate creation, learn how to create an estimate, and explore estimate templates to make the process easier for you.
An invoice is a payment request sent after work has been completed, or after a deposit, milestone, or billing stage is due.
For example, if you complete that same kitchen repair project, you would send an invoice showing the final amount due, the payment terms, and the due date.
Unlike an estimate, an invoice is not just informational. It tells the client that payment is now expected. It also becomes part of your accounting records until it is paid.
Invoices are used when:
If you need a place to start, learn how to create an invoice and browse invoice templates that help you put one together faster.
The estimate comes first.
In most cases, you send an estimate before the client approves the work. Once the client agrees and the job moves ahead, you later send an invoice to collect payment.
That is why estimates are part of the sales or approval stage, while invoices are part of the billing stage.
A client may never receive an invoice if they don't approve the estimate. However, if the work goes ahead, the estimate often becomes the reference point for what will later appear on the invoice.
Not by itself. An estimate doesn't automatically function as an invoice, because it does not ask for payment and usually does not include a due date.
However, many businesses use the estimate as the starting point for the final invoice. Once the client approves the work, the estimate can be converted into an invoice with the final pricing, payment terms, and amount due.
Practical Example
Imagine a designer sends a client an estimate for a website project:
Design work: $1,200
Revisions: $300
Total estimated cost: $1,500
The client approves the work.
After the project is complete, the designer sends an invoice:
Website design project: $1,500
Payment terms: Net 14
Total due: $1,500
In this case, the estimate helped win approval. The invoice is what requests payment.
An estimate is used before the work starts to show expected pricing. An invoice is used after work is done, or when payment is due, to request payment. Use the estimate to set expectations and the invoice to collect the money.
Use our estimate generator to send professional estimates, then convert an approved one into an invoice. Try it free for 14 days.
Create your first estimate now
