Invoice Dates and Billing Periods Guide

What is an invoice date?

An invoice date is the date shown on an invoice to indicate when the invoice was issued. It is one of the main reference points used to identify when the billing document was created and sent to the customer.

The invoice date can affect payment timing because payment terms are often measured from the date of the invoice. For example, an invoice dated 10 August with payment terms of 30 days may have a due date approximately 30 days later.

Keeping invoice dates accurate also makes it easier for businesses to organise invoices chronologically and match them with accounting records.

Where does the invoice date appear?

The invoice date normally appears near the top of the invoice alongside other important details such as the invoice number, due date, purchase order reference, and payment terms.

Placing the invoice date clearly near the top means the customer does not need to search through the document to understand when it was issued.

A consistent invoice layout also makes it easier for both the seller and customer to compare invoices and keep records organised.

What is a billing period?

A billing period is the period of time covered by an invoice. It tells the customer when the products, services, subscription, labour, or other charges shown on the invoice relate to.

For example, a consultant might invoice for work completed between 1 August and 31 August. A landlord might invoice for one month of rent, while another business could bill for services completed over a two week period.

Showing a billing period is especially useful when the same customer receives invoices regularly.

Common billing period examples

Billing periods can vary depending on the type of work and how often a customer is invoiced. Common examples include:

• Weekly
• Every two weeks
• Monthly
• Quarterly
• Per project stage
• Per milestone
• For a specific date range
• For a completed job

What is the difference between invoice date and billing period?

The invoice date and billing period describe two different things. The invoice date tells the customer when the invoice was issued, while the billing period tells them what period the charges relate to.

For example, a freelancer could complete work throughout July and issue the invoice on 1 August. In that situation, the billing period covers July while the invoice date is 1 August.

Showing both pieces of information can make recurring and project based invoices easier for customers to understand.

Invoice date vs due date

The invoice date and due date are also different. The invoice date records when the invoice was issued, while the due date identifies when payment is expected.

The gap between these dates depends on the payment terms. Some invoices may be due immediately, while others allow customers 7, 14, 30, 60, or another agreed number of days to pay.

Displaying both dates clearly prevents customers from confusing the day the invoice was created with the payment deadline.

Invoice date and due date example

For example, an invoice could contain the following dates:

• Invoice date: 5 August 2026
• Billing period: 1 July to 31 July 2026
• Payment terms: 30 days
• Due date: 4 September 2026

Why billing periods matter

Billing periods help customers understand exactly which work or service they are paying for.

This becomes particularly important when a business provides the same service repeatedly. Without a billing period, a customer receiving several similar invoices may find it difficult to identify which month or period each invoice covers.

Including the billing period can also help businesses compare invoices with timesheets, service records, project records, rental periods, and other supporting documents.

Billing periods for hourly work

Freelancers, contractors, consultants, and other professionals who charge by the hour may use billing periods to group work completed during a particular time range.

For example, an invoice could cover all billable hours completed between 1 August and 15 August. Individual tasks and hours can then be listed within the invoice items.

Using a clear period makes it easier for the customer to compare the invoice with timesheets or project records.

Billing periods for monthly services

Monthly billing is common for businesses providing ongoing services. The invoice can identify the month or exact date range covered by the payment.

For example, a social media manager might invoice for services provided from 1 August to 31 August, while a property related business could invoice for a monthly service period.

Using consistent monthly billing periods can make recurring customer records easier to organise.

Billing periods for project work

Project based businesses do not always use fixed weekly or monthly billing periods. Instead, invoices may relate to particular stages, milestones, or completed sections of work.

A contractor could issue an invoice after completing the first phase of a project, while a consultant could bill when an agreed milestone has been reached.

The invoice description should make it clear which stage or period of the project is being billed.

Can you backdate an invoice?

Backdating an invoice means using an invoice date earlier than the date the document is actually being created or issued.

Whether this is appropriate depends on the circumstances, accounting requirements, tax rules, and why the date needs to be changed. Businesses should avoid changing invoice dates simply to create a misleading record of when an invoice was issued.

If an invoice was created late or needs correcting, it is important to keep accurate records and use a date that reflects the transaction appropriately.

Why accurate invoice dates matter

Accurate dates make invoice records easier to understand and can affect payment deadlines, bookkeeping, tax reporting, and communication with customers.

An incorrect invoice date may cause confusion about when payment terms started, which accounting period the invoice belongs to, or whether the invoice relates to the correct transaction.

Checking dates before sending the invoice is therefore just as important as checking customer information, item descriptions, quantities, and totals.

Can the invoice date be after the work was completed?

Yes. Businesses commonly issue an invoice after completing the work or supplying the goods.

For example, work may be completed on 28 August and the invoice could be created on 30 August. The invoice date would normally reflect when the invoice was issued, while the service description or billing period can show when the work was completed.

Keeping these dates separate provides a clearer record than trying to make every date on the invoice identical.

Can the invoice date be before the due date?

Yes. In most ordinary invoices, the invoice date comes before the payment due date.

The time between them is determined by the agreed payment terms. For example, an invoice issued on 1 September with 14 day payment terms may have a due date around 15 September.

If payment is due immediately, the invoice date and due date could potentially be the same day.

What date should you use on an invoice?

The date used should accurately reflect when the invoice is being issued according to the business process and any applicable accounting or tax requirements.

Do not choose invoice dates randomly simply to change when payment appears due. Consistent dating makes financial records easier to manage and helps customers understand when invoices were sent.

If your business has specific accounting requirements, confirm how invoice dates should be recorded before issuing the document.

How payment terms work with invoice dates

Payment terms explain how long the customer has to pay after the invoice is issued or according to another agreed reference point.

For example, Net 30 generally means payment is expected within 30 days under the agreed terms. Showing both the payment terms and an exact due date can make the deadline easier for the customer to understand.

The invoice date therefore plays an important role in calculating payment timing when the terms are based on the date of issue.

Common invoice date mistakes

Invoice dates should be checked before sending the document. Common mistakes include:

• Using the wrong year
• Entering the wrong month
• Confusing the invoice date with the due date
• Using an incorrect billing period
• Leaving dates from a copied invoice unchanged
• Using inconsistent date formats
• Setting a due date that does not match the payment terms

How to show dates clearly on an invoice

Use clear labels such as Invoice Date, Due Date, and Billing Period so customers can immediately understand what each date represents.

Choose a consistent date format across your invoices. Depending on your location and customers, this might be day, month, year or month, day, year.

When invoicing international customers, writing the month as text or otherwise using an unambiguous format can help prevent confusion between different regional date conventions.

Check invoice dates before sending

Before sending an invoice, check that the invoice date, due date, and billing period are correct and consistent with the work completed and payment terms.

You should also review the customer details, invoice number, products or services, quantities, rates, taxes, discounts, notes, and final balance.

Correcting a date before sending the invoice is much easier than having to explain or replace an incorrect invoice later.

Create an invoice with clear dates

A professional invoice should make it easy for the customer to understand when it was issued, what they are being billed for, and when payment is due.

InvoiceAtlas lets you enter your invoice date, due date, payment terms, customer information, invoice items, taxes, discounts, notes, and final balance.

Once the information has been checked, the completed invoice can be downloaded as a PDF and sent directly to the customer.