Alberta 31-Day Invoice Rule: Proper Invoice Checklist

The Alberta 31-day invoice rule requires contractors on covered projects to give the owner a proper invoice at least every 31 days. Missing that cadence can delay cash flow before the 28-day payment clock even begins. Alberta's content rules also require an express declaration that the document constitutes a proper invoice.

However, those details make Alberta different from Ontario. There is no statutory seven-day window that automatically deems a deficient invoice proper because the owner stayed silent. For an Alberta contractor, the safest workflow is to submit a complete proper invoice on schedule and preserve proof of receipt.

Specifically, this guide explains the private-sector rules in force under Alberta's Prompt Payment and Construction Lien Act (PPCLA) as of August 13, 2026. It also identifies the separate treatment required for Alberta government public works.

What is the Alberta 31-day invoice rule?

Specifically, section 32.1(6) of the Prompt Payment and Construction Lien Act requires contractors to give owners a proper invoice at least every 31 days. The statutory exception applies where the contract includes testing and commissioning requirements and those conditions have not been met, subject to the regulations.

Therefore, a contractor performing ongoing work should build a billing cycle that does not leave more than 31 days between proper invoices. A familiar "monthly" process may work, but only if the actual submission dates remain inside the statutory cadence. A month-end invoice sent late in the following month can create a gap longer than 31 days.

However, the rule governs the contractor's proper invoice to the owner. It does not simply turn every subcontractor invoice into the statutory owner-facing proper invoice. Subcontractors still have a direct operational interest in the cycle. They must send their billing information early enough for the contractor to include it accurately upstream.

Notably, the Act does not expressly say that an invoice issued on day 32 is void. Still, contractors should not treat the cadence as optional. Late billing creates a compliance problem and moves every payment event that depends on receipt of a proper invoice. The legal consequences of a specific late submission may depend on the contract and facts.

Overall, Alberta's prompt-payment regime has applied to new covered construction contracts since August 29, 2022. The province's current prompt-payment guidance confirms that older contracts extending beyond August 29, 2024 had to become compliant by that date.

The eight elements of an Alberta proper invoice

First, the 31-day cadence matters only if the document is a proper invoice. Section 32.1(1) defines that term as a written bill or other request for payment for work done or materials furnished in respect of an improvement under a contract.

Specifically, for a private-sector PPCLA project, the request must contain:

1. The contractor's name and business address. Use the legal contracting entity and a reliable business address.
2. The invoice date and billing period. State both the date of the proper invoice and the period when the contractor did the work or supplied the materials.
3. The authority for the work. Identify the written or verbal contract, purchase order, change order, field direction or other source that authorized the work or materials.
4. A description of the work or materials. Give enough detail to connect the request to the improvement and the relevant billing period.
5. The amount requested and corresponding payment terms. Break down the requested payment for the work or materials rather than presenting an unexplained total.
6. Payment-contact information. Include the name, title and contact information of the payment recipient.
7. The proper-invoice statement. Declare that the invoice constitutes a proper invoice.
8. Any prescribed information. Check the current legislation, regulations and contract before each project begins for additional requirements.

Additionally, the contract may add invoice requirements, subject to section 32.1(4). A contractor should use both the statutory checklist and the project-specific billing instructions. An invoice can satisfy the Act's base list but still face a contractual objection if it omits a valid agreed requirement.

For a broader introduction, see Tiercord's Alberta proper-invoice guide and proper-invoice checklist.

The sentence that is easy to miss

Importantly, Alberta expressly requires a declaration that the document constitutes a proper invoice. That is not decorative wording. It is one of the listed elements in section 32.1(1)(g).

Therefore, a practical statement is:

This invoice is intended to constitute a proper invoice for the purposes of the Prompt Payment and Construction Lien Act (Alberta).

Overall, the Act does not prescribe those exact words. The point is to communicate the required intention clearly. Place the statement on the invoice itself. Do not rely on an email subject line or a separate transmittal that may later become detached from the payment record.

This one sentence should appear in the contractor's Alberta invoice template by default. It is safer than asking a project administrator to remember it every 31 days.

When does the 28-day payment clock begin?

Importantly, the owner's payment deadline does not depend on the end of the billing period, work approval or invoice drafting. Under section 32.2(1), it runs from the owner's receipt of the proper invoice.

Accordingly, an owner who owes money under that invoice must pay the amount payable no later than 28 calendar days after receipt. If the owner disputes all or part of the invoice, section 32.2(2) requires a notice of dispute no later than 14 calendar days after receipt. The prescribed notice must identify the amount withheld and detail all reasons for non-payment.

However, the undisputed portion remains payable on the 28-day clock. Sending a dispute notice for one line item does not automatically suspend the whole invoice.

Therefore, the sequence is:

• Day 0: The owner receives a complete proper invoice.
• By day 14: The owner gives a compliant notice of dispute for any amount it will not pay.
• By day 28: The owner pays the amount payable, including the undisputed portion.
• After owner payment: The contractor generally has seven calendar days to pay subcontractors for work or materials included in the proper invoice, subject to the Act's downstream notice rules.

These are calendar-day periods. Still, Alberta's time-computation and holiday rules can affect the result. So can the delivery method and proof of actual receipt. Tiercord's Alberta payment-deadline guide explains the wider payment chain.

Why proof of receipt is as important as the invoice date

For example, an invoice dated June 30 but left in a draft folder until July 3 does not start the payment clock on June 30. The receipt event is the anchor.

Therefore, contractors should keep a record that connects the final invoice to its delivery:

• the final PDF or electronic invoice version;
• the email, portal receipt or other transmission record;
• the date and time of delivery;
• the recipient or project portal used;
• attachments and supporting schedules sent with it; and
• any acknowledgment, rejection or notice of dispute.

Additionally, do not overwrite the submitted file when making a correction. Preserve the original, the revision and the correspondence showing why the parties changed it. That record can become important in a payment dispute or adjudication.

Can the owner require certification before invoicing?

Generally, no. Importantly, section 32.1(3) says a contract term that makes giving a proper invoice conditional on prior certification by another person or prior owner approval is of no force or effect, subject to section 32.1(4).

However, the main statutory qualification concerns contractual testing and commissioning. A genuine testing-and-commissioning provision may delay invoicing for the affected work when the required conditions have not been met. Do not use that exception as a general label for an ordinary approval process.

Therefore, this distinction matters during contract review. A clause that says "the contractor may invoice only after the consultant approves the progress claim" may conflict with the PPCLA. The Act may treat a narrow condition tied to actual testing and commissioning differently.

Accordingly, contractors should flag these clauses before work begins, not after the owner rejects the first invoice. Owners should also separate their internal review process from the contractor's statutory right to give a proper invoice.

Can an Alberta proper invoice be revised?

Yes, but the Act limits the process. Specifically, section 32.1(5) lets the parties revise a proper invoice only if:

• the parties agree to the revision;
• the date of the proper invoice is not changed; and
• the revised invoice continues to meet the proper-invoice requirements.

That means a unilateral replacement invoice is not the clean statutory path. It also means the parties should not re-date a revision merely to create a new payment timeline.

Therefore, record the agreement to revise in writing. Mark the new document clearly as a revision, retain the original invoice date and identify the fields or amounts that changed. If the parties disagree about a revision, obtain project-specific advice. Do not assume that the revision resets or cancels a statutory deadline.

Alberta has no seven-day deemed-proper rule

Importantly, this is one of the most important differences between Alberta and Ontario.

Ontario now has a process under which an invoice may become deemed proper if the recipient does not give a timely written deficiency notice. Alberta's PPCLA contains no equivalent seven-day deeming provision for a deficient invoice.

Consequently, silence does not reliably cure a missing Alberta element. If the contractor omits the section 32.1(1)(g) statement, the billing period or another required item, it should not assume the owner's failure to object transforms the document into a proper invoice.

Nevertheless, owners should not exploit that distinction by quietly shelving questionable bills. A prompt written response creates a clearer record and gives the contractor a chance to address the issue. But an operational courtesy is not the same as Ontario's statutory deficiency-notice mechanism.

Ultimately, the safest Alberta 31-day invoice rule workflow is preventive: validate the document before delivery, then calculate the 14-day and 28-day dates from confirmed receipt. See Tiercord's notice-of-non-payment guide for the different notices used when payment is withheld.

A worked example

Specifically, assume a covered private construction contract begins on September 1. The contractor gives the owner a complete proper invoice on September 30, and the owner receives it that day.

The invoice includes the contractor's identity, the September billing period, the contract and approved change-order references, a breakdown of the work, the payment contact and the express proper-invoice statement.

Accordingly, the key events are:

• The next proper invoice should be delivered within the next 31-day cycle during ongoing performance.
• The owner has 14 calendar days from September 30 to give a compliant notice of dispute.
• The amount payable is due 28 calendar days after September 30.
• If the owner pays, the contractor's downstream seven-day payment obligation generally follows for covered subcontractor amounts included upstream.

However, change one fact. The contractor dates the invoice September 30 but the owner does not receive it until October 3. The statutory receipt-based clocks start on October 3, not September 30.

Next, change another fact. The invoice omits the express proper-invoice statement. Alberta has no seven-day deeming rule that automatically fixes the omission through owner silence. The contractor should address the defect promptly and document any agreed revision without changing the original invoice date.

Private projects and Alberta public works are not interchangeable

Importantly, this article focuses on projects governed by the PPCLA. Alberta government project contracts are subject to the Public Works Act and are exempt from the PPCLA timelines, according to the province's current guidance.

However, that does not mean public works lack prompt payment. Amendments effective April 1, 2025 created a separate prompt-payment and adjudication framework for new public works contracts. Alberta Infrastructure's industry fact sheet describes a 31-day proper-invoice cadence and separate payment rules under that regime.

Therefore, do not copy a private-project checklist into a public-works file without checking the governing Act and contract. The required invoice content and downstream structure are not identical. Confirm at intake whether the owner is the Crown and which statutory framework applies.

A practical 31-day billing workflow

Overall, the Alberta 31-day invoice rule is easier to manage as a repeatable control than as a calendar reminder.

1. Classify the project

First, confirm the province, contract date, owner and governing statute. Separate PPCLA projects from Alberta public works and from federal projects located in Alberta.

2. Create the billing calendar

Next, set the submission date when the contract starts and again after each proper-invoice delivery. Do not rely on a generic "month end" task if holidays, weekends or approval habits can push actual delivery past 31 days.

3. Collect subcontractor information early

Then, set an internal cutoff far enough ahead to review subcontractor billings, change orders and supporting records. Tell subcontractors exactly what they must submit for the contractor to include their work upstream.

4. Validate all statutory and contractual fields

Use the eight-part PPCLA checklist together with the contract's valid billing requirements. Confirm the proper-invoice statement appears on the final rendered document.

5. Deliver through an approved channel

Use the contractually designated email address or portal. Save objective evidence of the delivery time and the exact version transmitted.

6. Start the receipt-based clocks

Track the owner's 14-day dispute deadline and 28-day payment deadline from confirmed receipt. Do not anchor them to the file name or invoice date unless receipt occurred that day.

7. Preserve the downstream allocation

Specifically, keep a schedule showing which subcontractor work and materials the contractor included in the owner-facing proper invoice. That allocation supports the downstream payment and notice process.

8. Escalate exceptions quickly

Address a rejection, disputed receipt date, missing field or contested testing condition immediately. Alberta's lack of a deemed-proper rule makes passive waiting a poor strategy.

Common mistakes to avoid

The most frequent risks are procedural rather than mathematical:

• treating "monthly" as automatically compliant without checking the actual gap between delivery dates;
• omitting the express proper-invoice statement;
• identifying the project but not the contractual authority for extra work;
• using an invoice date as proof of receipt;
• accepting a general prior-approval condition without reviewing section 32.1(3);
• revising an invoice unilaterally or changing its original date;
• assuming owner silence cures a deficient invoice; and
• applying the PPCLA checklist unchanged to a Public Works Act project.

A consistent pre-send review prevents most of these errors. It also gives the contractor a cleaner record if a payment dispute proceeds to construction adjudication.

Frequently asked questions

Does Alberta require a proper invoice every 31 days?

Yes. Specifically, for covered PPCLA projects, section 32.1(6) requires contractors to give the owner a proper invoice at least every 31 days during the work, subject to the statutory testing-and-commissioning qualification and the regulations.

Does the owner have 28 days from the invoice date to pay?

Not necessarily. Instead, the 28-day payment period runs from the owner's receipt of a proper invoice. The invoice date and receipt date may be different, so preserve delivery evidence.

Must an Alberta invoice say that it is a proper invoice?

Yes. Therefore, put the statement on the invoice itself. Section 32.1(1)(g) requires the contractor to declare that the document constitutes a proper invoice.

Is a consultant certificate required before the contractor can invoice?

Generally, a contract cannot make giving a proper invoice conditional on prior certification or owner approval. The Act preserves a qualification for contractual testing and commissioning, subject to the legislation and the specific facts.

Does silence make a deficient Alberta invoice proper?

No equivalent to Ontario's seven-day deemed-proper rule appears in Alberta's PPCLA. Therefore, contractors should correct deficiencies promptly through the statutory revision process rather than rely on silence.

Does the same checklist apply to Alberta government projects?

No. Instead, Alberta government public works use a separate prompt-payment framework under the Public Works Act. Confirm the governing statute and contract before applying any deadline or form.

The bottom line

The Alberta 31-day invoice rule is not just a reminder to bill regularly. Each submission must be timely, complete, contract-aware and provably received. The proper-invoice statement, billing period, authority for the work and delivery record all matter because the 28-day clock depends on a proper invoice reaching the owner.

Build those checks into the invoice template and project calendar. Then track the dispute, payment and downstream dates from the receipt event rather than from assumptions.

Tiercord tracks Alberta's prompt-payment clocks, proper-invoice requirements and downstream obligations in one project record. Explore the full Alberta prompt-payment guide or start a Tiercord workspace to put the workflow into practice.

This article provides general information, not legal advice. Construction contracts, transition rules, public-works status, delivery facts and project-specific terms can change the result. Consult an Alberta construction lawyer about your circumstances.