Host-country decision
The competent government authority decides whether and how mitigation outcomes may be authorised for international use.
Article 6 and international carbon markets
What is a Letter of Authorisation?
A Letter of Authorisation, often shortened to LoA, records a host country’s authorisation of specified mitigation outcomes for a defined international use. Its scope matters: the activity, units, time period, authorised entities and intended purpose should all be read carefully.
The short answer
A government authorisation with a defined scope
An LoA is issued by an authorised host-country body. It identifies the mitigation outcomes and international use being authorised, together with the entities, periods and conditions covered. It should not be treated as a blanket approval for every credit from a project.
Specific scope
The authorisation may cover named activities, entities, vintages, volumes and uses. Anything outside that scope requires separate confirmation.
Accounting commitment
Where required, the host country commits to the Article 6 accounting and reporting needed to avoid double counting.
Article 6 pathway
How authorisation fits into an international transfer
The exact national process varies, but a credible pathway connects project information, government authorisation, registry records and international reporting.
Define the intended use
Identify whether outcomes are intended for another country’s NDC, CORSIA or another international mitigation purpose.
Submit project evidence
Provide the host authority with the activity, methodology, expected outcomes, safeguards and requested scope of authorisation.
Receive and record authorisation
The competent authority issues its decision and the relevant programme or registry links it to the covered activity and units.
Transfer, track and report
Once the applicable first-transfer event occurs, the outcomes are tracked and the host country applies the required accounting and reporting.
Read the scope
What an LoA should make clear
Terminology and document formats differ between countries. The practical question is whether the letter clearly covers the outcomes and use being proposed.
Issuing authority and legal basis
Mitigation activity or cooperative approach
Authorised entities or participants
Intended international use
Covered vintages, periods or volumes
Definition or timing of first transfer
Corresponding-adjustment commitment
Conditions, limits and reporting requirements
Project readiness
Authorisation starts with a well-evidenced project
Government engagement is stronger when the project can demonstrate a credible methodology, clear ownership and benefit-sharing arrangements, robust monitoring and alignment with national climate priorities. An LoA does not replace those foundations.
Different uses
The purpose changes with the market framework
Article 6 cooperation
A host country may authorise mitigation outcomes for use towards another country’s NDC or for another international mitigation purpose. Authorised outcomes become ITMOs upon the applicable first transfer.
CORSIA
For relevant CORSIA units, host-country authorisation or attestation supports avoidance of double claiming. The units must still satisfy all current ICAO programme and unit-level eligibility rules.
Read our CORSIA guide →Voluntary use
Many voluntary credits do not require Article 6 authorisation. Some buyers seek authorised units for particular claims or procurement policies, but the intended use and accounting treatment must be defined precisely.
Avoiding double counting
Authorisation and corresponding adjustments are connected, but distinct
The LoA records the host country’s authorisation and commitment. The corresponding adjustment is the accounting action used to reflect the authorised transfer or use in the host country’s Article 6 reporting. Buyers should check both the authorisation and the arrangements for evidencing the adjustment.
Authorisation
The host country specifies what is authorised, for whom and for which international purpose.
First transfer
The relevant event turns an authorised mitigation outcome into an internationally transferred mitigation outcome under Article 6 accounting.
Adjustment and reporting
The host country accounts for the authorised use through its Article 6 and Biennial Transparency reporting arrangements.
Real-world outcomes
The document supports accounting; the project delivers the impact
An LoA can clarify sovereign consent and international accounting, but environmental integrity still depends on the underlying activity. Methodology, additionality, monitoring, independent verification, safeguards and community outcomes remain essential.
Important limits
What an LoA does not prove on its own
Authorisation is an important sovereign and accounting signal, not a substitute for project or unit due diligence.
It does not guarantee carbon-credit quality
It does not make every project unit eligible
It does not replace validation or verification
It does not confirm that a corresponding adjustment has already been applied
It does not override programme or market exclusions
It does not determine the buyer’s permitted public claim
Due diligence
Questions to ask before relying on an LoA
Review the original document alongside the registry record, current host-country rules and the requirements of the intended market.
Was it issued by the competent national authority?
Does it name the relevant activity and participants?
Does it cover the exact units, periods and volumes?
Is the intended international use explicit?
What event is treated as first transfer?
How will the corresponding adjustment be evidenced?
Are there conditions, expiry dates or revocation provisions?
Do the programme and registry records match the letter?
This page provides general information and is not legal, regulatory or claims advice. Requirements vary by host country, carbon-crediting programme and intended use. Obtain current specialist advice for a specific transaction.
CO2balance support
Building an authorisation-ready evidence base
CO2balance can support project feasibility, methodology selection, documentation, monitoring and engagement planning. The host-country authority retains responsibility for its authorisation decision, and formal legal or compliance advice should come from appropriately qualified advisers.
Frequently asked questions
Letter of Authorisation questions
What does LoA stand for?
LoA stands for Letter of Authorisation. In carbon markets, it commonly refers to a host-country document authorising specified mitigation outcomes for a defined international use.
Who issues an LoA?
The competent authority designated under the host country’s laws and Article 6 arrangements issues the authorisation. The responsible ministry or agency differs by country.
Does every voluntary carbon credit need an LoA?
No. Many voluntary credits are issued and used without Article 6 authorisation. Whether an LoA is needed depends on the intended use, buyer requirements, host-country rules and programme requirements.
Does an LoA automatically create an ITMO?
No. Authorised mitigation outcomes become ITMOs when the applicable first-transfer event occurs and the outcomes enter the relevant Article 6 tracking and accounting process.
Is an LoA the same as a corresponding adjustment?
No. The LoA records the authorisation and relevant commitments. A corresponding adjustment is the accounting action applied and reported by the host country to avoid double counting.
Is an LoA required for CORSIA?
For relevant post-2020 CORSIA units, host-country authorisation or attestation to avoid double claiming is a key eligibility condition. All other ICAO programme, scope, date and unit-level conditions must also be met.
Can an authorisation be limited or conditional?
Yes. It may be limited by activity, participant, vintage, volume, use, period or other conditions. The exact wording and registry treatment should be reviewed carefully.
Primary sources: UNFCCC, Article 6 of the Paris Agreement and voluntary standardised authorisation template; ICAO, CORSIA Eligible Emissions Units. Last reviewed July 2026.
Planning an authorised carbon project?
Talk to CO2balance about project readiness, host-country engagement and the evidence needed for an informed authorisation pathway.