How much is Illinois's Sustainable Aviation Fuel Purchase Credit worth, and are there any caps or carry-forward limits on using it?

Plain-English summary

Illinois offers a Sustainable Aviation Fuel Purchase Credit (SAFPC) worth $1.50 per gallon of sustainable aviation fuel (SAF) purchased or used by an air common carrier, as long as the carrier certifies the fuel was used in Illinois. The credit runs from July 1, 2023 through December 31, 2032, and only the SAF portion of each gallon of aviation fuel (as opposed to conventional jet fuel blended in) is eligible.

The carrier uses SAFPC by certifying to its fuel seller that it is applying the credit against all or part of its liability for the 6.25% state rate under the Use Tax Act or Service Use Tax Act on aviation fuel purchases. The credit only offsets that 6.25% state rate — it does not apply to local taxes.

An air common carrier asked the Department to confirm its reading of the program's limits. The Department confirmed: there is a statewide annual cap of 10,000,000 gallons of soybean oil feedstock for SAFPC purposes — once carriers collectively purchase SAF containing that much soybean oil feedstock in a calendar year, no more SAFPC can be earned on soybean oil-derived SAF that year (and if reported credit exceeds the cap, it gets proportionately reduced). But there is no similar cap on SAFPC earned from SAF made from other eligible feedstocks, such as used cooking oil, animal fat, or waste (distillers) corn oil.

SAFPC earned in one year but not fully used that year can be carried forward to offset future years' aviation fuel tax liability, but it is non-transferable and non-refundable, and any credit still unused as of December 31, 2032 simply expires.

What this means for you

Air common carriers

If you purchase SAF for use in Illinois, you can certify $1.50 per gallon toward your 6.25% state Use Tax or Service Use Tax liability on aviation fuel. Track your SAF purchases by feedstock type, since soybean oil-derived SAF is subject to the statewide 10,000,000-gallon annual cap while other feedstocks (used cooking oil, animal fat, waste corn oil) are not. You must report your SAF purchases and SAFPC earning/usage to the Department (see Form ST-70-C), and any credit you don't use in the year earned carries forward — but only until it expires on December 31, 2032, since it can't be transferred or refunded.

Fuel suppliers to airlines

When a carrier certifies that it is using SAFPC to satisfy some or all of its use tax liability on an aviation fuel purchase, that certification is how the credit gets applied at the point of sale. Sellers should be prepared to accept and document these certifications under 86 Ill. Adm. Code 130.333.

Accountants and tax professionals

The cap in 86 Ill. Adm. Code 130.333(a)(5) (and the parallel statutory provisions at 35 ILCS 105/3-87 and 35 ILCS 110/3-72) applies only to soybean oil-derived SAF, on a statewide aggregate basis across all program participants — it is not a per-taxpayer cap and does not touch SAFPC generated from other feedstocks. When advising a client on carry-forward planning, remember SAFPC is non-refundable, non-transferable, and hard-expires at the end of 2032, so unused credits near that date have no residual value.

Common questions

Q: How much is the Sustainable Aviation Fuel Purchase Credit worth?
A: $1.50 per gallon of sustainable aviation fuel purchased or used by an air common carrier and certified as used in Illinois, available from July 1, 2023 through December 31, 2032.

Q: Is there a limit on how much SAFPC can be earned each year?
A: Only for soybean oil-derived SAF. Once air common carriers statewide have collectively purchased SAF containing 10,000,000 gallons of soybean oil feedstock in a calendar year, no more SAFPC can be earned on soybean oil-derived SAF for the rest of that year (and reported credit above the cap is reduced proportionately). There is no annual cap on SAFPC earned from SAF made from other feedstocks, such as used cooking oil, animal fat, or waste corn oil.

Q: Can unused SAFPC be carried forward to a later year?
A: Yes. Properly documented and reported SAFPC earned in a year but not fully used that year can be carried forward to offset future aviation fuel tax liability, but only until the credit expires on December 31, 2032. SAFPC is not refundable and not transferable.

Q: What tax does SAFPC actually offset?
A: The 6.25% state rate of Use Tax or Service Use Tax due on the purchase of aviation fuel. The purchaser certifies to the seller that it is using SAFPC to satisfy all or part of that liability.

Q: What reporting is required to use the credit?
A: Air common carriers must account for the earning and usage of SAFPC on their monthly returns and periodically report the gallons of soybean oil feedstock (and other SAF) purchased, in the form and manner required by the Department, using Form ST-70-C (Sustainable Aviation Fuel Purchase Credit Certification).

Citations and references

• 86 Ill. Adm. Code 130.333 (Sustainable Aviation Fuel Purchase Credit, generally)
• 86 Ill. Adm. Code 130.333(a)(1) (only the SAF portion of each gallon of aviation fuel is eligible)
• 86 Ill. Adm. Code 130.333(a)(4) (SAFPC reporting requirements; Form ST-70-C)
• 86 Ill. Adm. Code 130.333(a)(5) (10,000,000-gallon annual statewide cap on soybean oil-derived SAF credits)
• 86 Ill. Adm. Code 130.333(b) (definition of qualifying sustainable aviation fuel)
• 86 Ill. Adm. Code 130.333(c)(1) (credit applies only to the 6.25% State tax rate)
• 35 ILCS 105/3-87 (Use Tax Act — soybean oil-derived SAF cap)
• 35 ILCS 110/3-72 (Service Use Tax Act — soybean oil-derived SAF cap)
• 2 Ill. Adm. Code 1200.110 (Private Letter Ruling procedures)
• 2 Ill. Adm. Code 1200.120 (General Information Letters)

Source

• Landing page: Illinois Sales Tax Letter Rulings, 2025
• Original PDF: st25-0048-gil.pdf

Original ruling text

ST 25-0048-GIL

09/11/2025

SUSTAINABLE AVIATION FUEL

From July 1, 2023 through December 31, 2032, sustainable aviation fuel (“SAF”)
sold to or used by an air common carrier, certified by the carrier to be used in
Illinois, earns a Sustainable Aviation Fuel Purchase Credit (“SAFPC”) in the amount
of $1.50 per gallon of SAF purchased. To use the SAFPC, the purchaser shall certify
to the seller of the aviation fuel that the purchaser is satisfying all or part of its
liability for the 6.25% tax under the Use Tax Act or the Service Use Tax Act that is
due on the purchase of aviation fuel by use of SAFPC. See 86 Ill. Adm. Code
130.333. (This is a GIL).

September 11, 2025
NAME
COMPANY
ADDRESS
Dear NAME:
This letter is in response to your letter dated June 13, 2025, in which you requested
information. The Department issues two types of letter rulings. Private Letter Rulings
(“PLRs”) are issued by the Department in response to specific taxpayer inquiries concerning
the application of a tax statute or rule to a particular fact situation. A PLR is binding on the
Department, but only as to the taxpayer who is the subject of the request for ruling and only
to the extent the facts recited in the PLR are correct and complete. Persons seeking PLRs
must comply with the procedures for PLRs found in the Department’s regulations at 2 Ill.
Adm. Code 1200.110. The purpose of a General Information Letter (“GIL”) is to direct
taxpayers to Department regulations or other sources of information regarding the topic
about which they have inquired. A GIL is not a statement of Department policy and is not
binding on the Department. See 2 Ill. Adm. Code 1200.120. You may access our website at
https://tax.illinois.gov/ to review regulations, letter rulings and other types of information
relevant to your inquiry.
The nature of your inquiry and the information you have provided require that we
respond with a GIL. In your letter you have stated and made inquiry as follows:
This is a General Information Letter requesting some guidance about the Title
86, Chapter I, Part 130, Section 130.333 Sustainable Aviation Fuel Purchase
Credit.
After review of the Administrative Code relative to this tax credit, we have a
few questions:

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September 11, 2025

1. Caps, or limits – While we see the Code’s annual limitation for the
   generation of this Sustainable Aviation Fuel Purchase Credits (SAFPC) to
   a maximum of 10 million gallons (in the statewide aggregate among all
   program participants) of soybean oil derived SAPC’s, we can see no limit
   on the annual generation of SAPC’s that are associated with SAF produced
   from feedstocks other than soybean oil. I.e. it appears that there is no limit
   on the number / quantity of SAFPC’s generated annually with respect to
   SAFPC’s associated with the use of SAF that is produced from Used
   Cooking Oil, Animal Fat, or waste (Distillers) Corn Oil. Is this a correct
   understanding with respect to annual limits for the number of SAFPC’s the
   program can generate for aviation fuel users in this state program?
2. Use limitations on the SAFPCs – We see in the Code that SAFPC’s are not
   refundable or transferable, and further – that any unused SAFPC’s
   effectively expire on December 31, 2032. These provisions imply that any
   SAFPCs earned in a particular year, that are not consumed, or used in that
   same year, can be carried forward. (Let’s use the example of calendar year
   2026) If an air common carrier uses 4,000,000 gallons of SAF in 2026, and
   therefore generates 4,000,000 x $1.50 per gallon used = $6,000,000 of
   SAFPCs, and only has an aviation fuel sales tax liability in 2026 of
   $5,000,000, then this “excess” of $1,000,000 of available SAFPC’s earned
   in 2026 would be able to be used against the air common carrier’s 2027
   aviation fuel sales tax liability. Is this a correct understanding in the ability
   to carry-forward SAFPC’s that are earned in one year, but not fully used in
   the same year (of earning?) Of course, we note that any SAFPC’s unused
   as of December 31 2032 will expire and will not be useable thereafter.
3. Soybean Cap provisions – With respect to the below language in the
   Administrative Code relative to the soybean oil-derived SAF, and how any
   (Soybean oil-derived SAF) exceedance is resolved:
   a. “Until January 1, 2033, on an annual basis, running from January
   through December each year, no credit may be earned by an air
   common carrier for soybean oil-derived SAF once air common carriers
   in this State have collectively purchased SAF containing 10,000,000
   gallons of soybean oil feedstock. [35 ILCS 105/3-87; 35 ILCS 110/3-72]
   If the amount of credit earned during any calendar year reported to the
   Department by air common carriers includes credit earned on soybean
   oil-derived SAF that exceeds 10,000,000 gallons of soybean oil
   feedstock, then the credit earned on soybean oil-derived SAF shall be
   reduced proportionately to meet this cap.”

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September 11, 2025
b. Our understanding is that this language/provision/intent only applies
to SAFPC’s associated with Soybean oil-derived SAF and has no effecton or relationship-to SAFPC earning that are associated with SAF
produced from other (eligible) feedstocks that also meets the eligibility
criteria for SAF as defined in the Code. Is this correct?
The main theme of these questions goes to program limitations. Our read of
the Code only indicates a cap, or limitation with respect to the annual amount
of soybean oil-derived SAFPC’s and that no cap or limitation exists on an
annual basis for SAFPC’s for any other reason. Is this correct?
We recognize that this is a General Information Letter, and your answers are
not legally binding. And we greatly appreciate any guidance in this context,
that you can provide.
DEPARTMENT’S RESPONSE:
From July 1, 2023 through December 31, 2032, sustainable aviation fuel (“SAF”) sold
to or used by an air common carrier, certified by the carrier to be used in Illinois, earns a
credit in the amount of $1.50 per gallon of SAF purchased. The credit earned is referred to
as the Sustainable Aviation Fuel Purchase Credit or SAFPC. Only that portion of each gallon
of aviation fuel that consists of SAF is eligible to earn the credit. 86 Ill. Adm. Code
130.333(a)(1). To use SAFPC, the purchaser shall certify to the seller of the aviation fuel that
the purchaser is satisfying all or part of its liability for the 6.25% tax under the Use Tax Act or
the Service Use Tax Act that is due on the purchase of aviation fuel by use of SAFPC. The
credit may be applied only to the 6.25% State rate of tax incurred on aviation fuel. 86 Ill.
Adm. Code 130.333(c)(1). SAF is generally described by the U.S. Department of Energy as
an alternative fuel made from non-petroleum feedstocks that reduces emissions from air
transportation. For a definition of SAF that qualifies for the credit, see 86 Ill. Code
130.333(b).
Until January 1, 2033, on an annual basis, running from January through December
each year, no credit may be earned by an air common carrier for soybean oil-derived SAF
once air common carriers in this State have collectively purchased SAF containing
10,000,000 gallons of soybean oil feedstock. 86 Ill. Adm 130.333(a)(5). There is, however,
no limit on the annual generation of SAFPCs that are associated with SAF produced from
feedstocks other than soybean oil.
SAFPC earned by an air common carrier expires on December 31, 2032. SAFPC is
non-transferable and non-refundable. Taxpayers must account for the earning and usage of
SAFPC on each monthly return filed with the Department, as deemed necessary by the
Department. In addition, to monitor the number of gallons of soybean oil feedstock included

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September 11, 2025
in the SAF purchased and to monitor the earning and usage of SAFPC, air common carriers
must periodically report this information in the form and manner required by the
Department. 86 Ill. Adm. Code 130.333(a)(4). See Form ST-70-C Sustainable Aviation Fuel
Purchase Credit Certification for further information. Properly documented and reported
SAFPCs earned in a particular year that are not consumed or used in that same year can be
carried forward until the credits expire on December 31, 2032. Any SAFPC’s unused as of
December 31, 2032 will expire and will not be useable thereafter.
I hope this information is helpful. If you require additional information, please visit
our website at https://tax.illinois.gov/ or contact the Department’s Taxpayer Information
Division at 800-732-8866.
Very truly yours,

Samuel J. Moore
Associate Counsel
SJM:sce