AIA A201 Notice of Claim: The 21-Day Requirement Explained
Published 3 October 2026 · 6 min read
If your project uses AIA A201-2017, General Conditions of the Contract for Construction, one of the most important claims questions is:
When does the 21-day notice period actually start?
Under the standard, unmodified AIA A201-2017 §15.1.3.1, Claims under that provision must be initiated within 21 days after either:
- the event giving rise to the Claim; or
- the claimant first recognizes the condition giving rise to the Claim,
whichever is later.
Section 15.1.3.1 applies where the condition giving rise to the Claim is first discovered before the correction period under §12.2.2 expires. Conditions first discovered after that period fall under §15.1.3.2, which does not prescribe the same 21-day deadline.
But 21 days is not a universal AIA deadline, and it is not a universal US construction-claims rule. Other A201 provisions contain separate notice requirements, and Supplementary Conditions or owner amendments may change the standard mechanism.
The first task is therefore not simply to count 21 days. It is to identify the operative contractual provision and event timeline.
What is a Claim under AIA A201-2017?
Under §15.1.1, a Claim is broadly a demand or assertion by one party seeking, as a contractual right:
- payment of money;
- a change in Contract Time; or
- other relief under the Contract.
It also covers other disputes or matters in question between the Owner and Contractor arising out of or relating to the Contract.
For subcontractors, do not assume the same mechanism applies directly. A201 principally governs the Owner-Contractor relationship. Subcontracts may incorporate upstream requirements while adding shorter deadlines, different recipients or flow-down obligations.
When does the 21-day period start?
For Claims governed by §15.1.3.1, there are two possible trigger points.
1. The event giving rise to the Claim
This may be an owner instruction, denial of access, late design information or another project event.
But the event itself may occur before the project team recognizes that it creates a potential contractual Claim.
2. First recognition of the condition giving rise to the Claim
Suppose access is restricted on August 1. The contractor initially believes it can resequence the work. By August 8, updated scheduling information shows the restriction may affect completion.
August 8 may be relevant to the recognition analysis, depending on the facts and any contract modifications.
But a later schedule update or scope review does not automatically establish a later trigger date. Earlier records may show that the condition giving rise to the Claim was already recognized, even though its consequences were not yet fully understood or quantified.
The key question is:
When did the project team first recognize the condition giving rise to the potential Claim?
That can be fact-sensitive and may turn on field reports, emails, RFIs, meeting records, cost discussions or schedule information.
Who receives an AIA A201 Notice of Claim?
Under standard §15.1.3.1, the Claim is initiated by notice to:
- the other contracting party;
- the Initial Decision Maker; and
- the Architect, by copy, if the Architect is not the Initial Decision Maker.
For a contractor making a Claim under the Owner-Contractor contract, the other party is the Owner.
Delivery method matters too.
Under unmodified §1.6.2, written Claim notice must be delivered to the other party's designated representative by certified or registered mail, or by courier providing proof of delivery.
An email to the owner's project manager should therefore not automatically be treated as satisfying the contractual Claim-notice procedure.
Always check the executed agreement and modifications for the required recipients, addresses and delivery method.
Notice is not the same as substantiating the Claim
The Article 15 notice mechanism initiates the Claim. It does not complete the substantiation.
The underlying Claim may later require evidence of:
- contractual entitlement;
- causation;
- schedule impact;
- cost;
- labor and equipment; and
- contemporaneous project records.
The sequencing point is simple:
Do not wait until the Claim is fully calculated before checking notice.
A contractor can recognize a potential contractual right before the final cost or delay impact has been established.
Additional-cost Claims may require action before 21 days
One of the biggest mistakes is assuming every additional-cost issue gives the contractor a full 21-day window.
Under §15.1.5, where the Contractor intends to make a Claim for an increase in the Contract Sum, the notice required by §15.1.3 must be given before the Contractor proceeds with the portion of the Work that is the subject of the Claim, subject to the emergency provisions in §10.4.
That may create a much earlier operational deadline.
If an instruction arrives Monday and the disputed work is due to start Wednesday, Wednesday may matter more than the outer 21-day period.
Not every issue follows the 21-day rule
A201 contains separate notice mechanisms for particular circumstances.
For example, §3.7.4, covering concealed or unknown conditions, has its own notice framework.
The practical rule is:
Do not identify a project issue and automatically jump to §15.1.3.1. First identify the contractual provision governing the event.
Only then determine which notice mechanics apply.
Supplementary Conditions can change the answer
The standard A201 wording is only the starting point.
Supplementary Conditions and owner amendments may change:
- the notice period;
- what starts the clock;
- required recipients;
- delivery method;
- required supporting information; or
- consequences of noncompliance.
Subcontracts may also impose shorter periods to preserve the general contractor's ability to meet its upstream deadlines.
The document that matters is therefore the executed contract package, not a clean copy of A201 found online.
Three short examples
Delay
Access is restricted on May 1. On May 6, a schedule update shows potential completion impact.
May 6 may be relevant to the recognition analysis, but earlier records could show recognition occurred sooner. The contractor should also check §15.1.6, the applicable delay provisions and any amendments.
Owner instruction
An Architect's instruction is issued on June 3. After reviewing the scope on June 6, the contractor concludes the work may be additional.
June 6 may be relevant, but the later scope review does not itself establish the trigger date. If additional Contract Sum will be claimed, §15.1.5 must also be checked before the affected work proceeds.
Unexpected additional work
A field condition requires substantially different work than expected.
Before assuming a 21-day deadline, determine whether §3.7.4 or another specific provision governs the event.
Five questions to determine your AIA notice deadline
What contractual provision governs the event? Is this an Article 15 Claim, concealed condition, change, delay or something else?
Has AIA A201-2017 been modified? Check Supplementary Conditions, amendments and owner requirements.
What are the two possible trigger dates? Identify the event date and the first recognition of the condition giving rise to the Claim, supported by the available records.
Does another provision require action sooner? Check whether notice is required before performing work, disturbing a condition or taking another step.
Who must receive notice, and how? Verify recipients, addresses and delivery method.
The answer should not simply be "21 days."
It should be a contract-to-event map showing the operative provision, possible trigger dates, competing deadlines and required recipients.
Contract deadline and legal enforceability are separate questions
AIA A201 creates contractual requirements. It does not create one nationwide US construction-claims regime.
US jurisdictions differ on issues such as strict compliance, actual notice, waiver, substantial compliance and prejudice. Public projects may also involve statutory or agency-specific requirements outside the AIA documents.
For project teams, the practical approach is to identify the contractual requirements early rather than rely on a later legal argument to excuse missed notice.
Frequently asked questions
How many days do you have to give notice of a Claim under AIA A201-2017?
Under unmodified §15.1.3.1, 21 days after the event giving rise to the Claim or after the claimant first recognizes the condition giving rise to it, whichever is later. Supplementary Conditions and owner amendments frequently change this period.
Does an email count as a Notice of Claim under AIA A201?
Not automatically. Under unmodified §1.6.2, Notice of Claims under §15.1.3 must be delivered to the designated representative by certified or registered mail, or by courier providing proof of delivery. Check the executed contract for any modification.
Who must receive an AIA A201 Notice of Claim?
The other contracting party and the Initial Decision Maker, with a copy to the Architect if the Architect is not serving as the Initial Decision Maker.
Can a contractor use the full 21 days before performing additional work?
No. Under §15.1.5, where the Claim is for an increase in the Contract Sum, notice must be given before the Contractor proceeds with the affected portion of the Work, except in the emergencies covered by §10.4.
Does the 21-day rule apply to concealed or unknown conditions?
Not directly. §3.7.4 contains its own notice framework for concealed or unknown conditions. Identify the governing provision before calculating any deadline.
Check your AIA claim deadline
When a potential Claim arises, Hecato maps the contract and project record against the operative notice provisions.
Upload:
- the executed contract and General Conditions;
- Supplementary Conditions and amendments;
- relevant instructions or correspondence; and
- key project dates.
Hecato can identify the relevant notice provisions, map them against the event chronology and surface the dates, recipients and requirements your team needs to review.
Hecato supports construction-claims analysis and workflow. It does not provide legal advice.