Instructions for Form 6627 (01/2026)

Environmental Taxes

Section references are to the Internal Revenue Code unless otherwise noted.

Revised: 01/2026

Instructions for Form 6627 - Introductory Material

Future Developments

For the latest information about developments related to Form 6627 and its instructions, such as legislation enacted after they were published, go to IRS.gov/Form6627.

What’s New

Section 4611 financing rate.

For 2026, the section 4611 Hazardous Substance Superfund financing rate is adjusted for inflation and increased to $0.18 per barrel. See Part I , later, and Rev. Proc. 2025-32, available at IRS.gov/irb/2025-45_IRB#REV-PROC-2025-32. Filers should use the Form 6627 (January 2026) revision to report their tax.

Expiration of oil spill liability taxes (IRS Nos. 18 and 21).

The section 4611 tax on crude oil received (domestic petroleum oil spill tax), or petroleum products entered (imported petroleum oil spill tax) expired after December 31, 2025.

Caution:

Don't enter the expired taxes on the lines for IRS Nos. 18 and 21 unless Congress extends the taxes. To find out if legislation extends the taxes so that you can report them on your 2026 tax return, go to IRS.gov/Form6627.

Section 4671 taxable substances.

The list of taxable imported chemical substances has been updated and 60 substances have been added. The effective date for addition is January 1, 2026. See Table of Taxable Imported Chemical Substances, later. For the updated list of taxable substances and the effective date for purposes of refund claims under section 4662(e), see Notice 2025-41, 2025-34 I.R.B. 325, available at IRS.gov/irb/2025-34_IRB#NOT-2025-41 and Notice 2025-51, 2025-41 I.R.B. 448, available at IRS.gov/irb/2025-41_IRB#NOT-2025-51.

Tax on ODCs.

The section 4681 tax rates for ozone-depleting chemicals (ODCs) are increased by statute for 2026. See Part IV , later.

Reminders

Taxable substance polyoxymethylene.

Polyoxymethylene was added to the list of taxable substances. For purposes of the section 4671 tax, the effective date for addition is October 1, 2024. The effective date for purposes of refund claims under section 4662(e) is July 1, 2022. See Table of Taxable Imported Chemical Substances, later, and Notice 2024-50, availabe at IRS.gov/irb/2024-26_IRB#NOT2024-50.

The Inflation Reduction Act of 2022 reinstated the section 4611 Hazardous Substance Superfund financing rate (petroleum Superfund tax rate) on domestic crude oil and imported petroleum products, effective January 1, 2023, and stated that the tax will be indexed for inflation beginning in 2024. Until December 31, 2025, the financing rate was two taxes: the Hazardous Substance Superfund rate that’s annually adjusted for inflation, on lines 3a, 4a, and 7; and the $0.09 per barrel Oil Spill Liability Trust Fund financing rate. The Oil Spill Liability Trust Fund financing rate expires on December 31, 2025. For 2024, the Hazardous Substance Superfund rate was adjusted for inflation and increased to $0.17 per barrel. See Part I , later, and Notice 2023-34, available at IRS.gov/irb/2023-48_IRB#NOT-2023-34.

Caution:

Due to the IRS’s acquiescence in a recent court case, the section 4611 tax on exported crude oil currently doesn’t apply. See AOD 2023-01, at IRS.gov/actions-on-decisions.

The Infrastructure Investment and Jobs Act reinstated the section 4661 excise tax on chemicals (other than ODCs) and the section 4671 tax on imported chemical substances, effective July 1, 2022, (they previously expired on December 31,1995).

• The tax rates for chemicals (other than ODCs) are listed on Form 6627, Part II.

• See Table of Taxable Imported Chemical Substances for a listing of taxable imported chemical substances and the IRS-provided tax rates for most of the substances. Any additional tax rates the IRS provides will be available either online or in the Table of Taxable Imported Chemical Substances when they become available. Taxpayers are reminded that they may calculate their own tax rates for imported chemical substances, regardless of whether the IRS has provided a tax rate.

• Rev. Proc. 2022-26 provides procedures for requesting a determination that a substance be added or removed. Rev. Proc. 2023-20 modifies Rev. Proc. 2022-26 for the date on which a taxable substance is added to the list of taxable substances for purposes of refund claims under section 4662(e).

• For updates, such as the not yet shown tax rates for taxable imported chemical substances, or substances recently added or removed, go to IRS.gov/Form6627. Also, see frequently asked questions and answers at IRS.gov/scetfaqs.

General Instructions

Purpose of Form

Use this form to figure the environmental taxes on domestic crude oil and imported petroleum products, chemicals (other than ozone-depleting chemicals (ODCs)), imported chemical substances, ODCs, imported products that used ODCs as materials in the manufacture or production of the product, and the floor stocks tax on ODCs. If you need more lines for any part of the form, prepare a continuation sheet using the same format as the part. Attach the continuation sheet with Form 6627 to Form 720, Quarterly Federal Excise Tax Return. See Pub. 510, Excise Taxes, for more information on environmental taxes. See the Instructions for Form 720 for information on when and where to file Form 6627.

Instructions for Form 6627 - Notices

Who Must File

For Petroleum

1. The operator of the refinery that receives crude oil;

2. The user of crude oil before tax is imposed; and

3. The person entering the petroleum products for consumption, use, or warehousing.

For Chemicals (Other Than ODCs)

The manufacturer, producer, or importer of chemicals who sells or uses those chemicals.

For Imported Chemical Substances

The importer of substances who sells or uses those substances.

For ODCs

1. The manufacturer or importer of ODCs who sells or uses those ODCs;

2. The importer of taxable products who sells or uses those products; and

3. For 2026. The person other than the manufacturer or importer of ODCs who holds ODCs for sale or use in manufacturing on January 1, 2026.

Specific Instructions

Part I. Tax on Petroleum (IRS Nos. 16 and 53)

The tax rate on domestic crude oil and imported petroleum products is the Hazardous Substance Superfund financing rate (petroleum Superfund tax rate). The petroleum oil spill tax rate expired December 31, 2025. For 2026, the petroleum Superfund tax rate is $0.18 per barrel.

Although the domestic crude oil or imported petroleum products are reported separately, there is no difference in tax rates. For domestic crude oil, report the petroleum Superfund tax rate on IRS No. 53. For imported petroleum products, report the petroleum Superfund tax rate on IRS No. 16.

Crude oil.

Tax is imposed on domestic crude oil when it is received at a U.S. refinery. Crude oil includes crude oil condensates and natural gasoline. The operator of the refinery is liable for the tax. Tax is imposed on imported crude oil received at a U.S. refinery unless the imported petroleum products tax was imposed when the imported crude oil was entered into the United States. The operator of a U.S. refinery that receives imported crude oil must establish that tax was previously imposed on the imported crude oil.

User of crude oil.

Tax is imposed on domestic crude oil that’s used before it is received at a U.S. refinery. The user is liable for the tax. Crude oil used for extracting oil or natural gas on the premises where the crude oil is produced is not taxable.

Imported petroleum products.

Tax is imposed on imported petroleum products when they are entered into the United States for use, consumption, or warehousing. Petroleum products include crude oil, refined and residual oil, and other liquid hydrocarbon refinery products. The person entering the petroleum product into the country is liable for the tax.

The tax on petroleum is imposed only once on any imported petroleum product. The enterer must provide documentation of the tax imposed on imported crude oil to the refinery operator if requested by the refinery operator.

Fractional barrels.

Fractional barrels are taxed at a proportionate rate using the fraction produced by the number of gallons in the barrel over 42 gallons. Multiply the resulting fraction by $0.18 per barrel petroleum Superfund tax rate.

Part III. Tax on Imported Chemical Substances, IRS No. 17

The imported chemical substance tax is equal to the chemical tax that would have been imposed on the taxable chemicals (listed in Part II of Form 6627) used as materials in the manufacture of the substance if such substance had been manufactured in the United States. See Table of Taxable Imported Chemical Substances for the substances to which the imported substance tax applies.

To figure the tax, you’ll generally need to know the ratio of the weight of each taxable chemical used to make the substance to the total weight of the substance (the conversion factor). If you don’t have enough information to determine the conversion factor and the IRS has provided a tax rate for the substance, either online or in Table of Taxable Imported Chemical Substances, then that tax rate applies. If you don’t have enough information to determine the conversion factor and the IRS hasn’t provided a tax rate for the substance, then the tax is 10% of the appraised entry value of the substance.

Follow the steps, next, to figure the tax for Part III, lines 1 through 3.

Column (a).

Enter the imported chemical substance subject to tax.

Column (b).

Enter the number of tons of the substance imported and sold or used.

Column (c).

Enter each taxable chemical (listed in Part II of Form 6627) used in the manufacture of the substance. If using an IRS-provided tax rate or a tax rate based on 10% of the appraised entry value of the substance, there’s no need to enter information in column (c).

Column (d).

Enter the conversion factor for each taxable chemical or the appraised entry value of the total amount of the substance. If using an IRS-provided tax rate, there’s no need to enter information in column (d).

Column (e).

Enter the tax rate of each taxable chemical from Part II of Form 6627. If you don’t have enough information to determine the conversion factor and are using an IRS-provided tax rate, enter that tax rate here. If you don’t have enough information to determine the conversion factor and you’re figuring the tax based on the appraised entry value, enter 10% here.

Column (f).

Multiply the number of tons in column (b) by the conversion factor in column (d) by the rate in column (e) for each taxable chemical listed. If you don’t have enough information to determine the conversion factor and the IRS has provided a tax rate, multiply column (b) by column (e). If you don’t have enough information to determine the conversion factor and the IRS hasn’t provided a tax rate, you must use the appraised entry value to figure the tax. To figure the tax using the appraised entry value, multiply the appraised entry value in column (d) by the rate (10%) in column (e).

Part IV. Tax on Ozone-Depleting Chemicals (ODCs), IRS No. 98

Caution:

For section 4681, these instructions are to be used for tax year 2026.

ODCs for 2026.

The following ODCs are taxed for 2026 as follows.

Caution:

The tax per pound rates above are figured using the ozone-depletion factor. Do not multiply the tax per pound by the ozone-depletion factor.

Mixture elections.

Generally, the creation of a mixture containing one or more ODCs by the manufacturer or importer of an ODC is treated as the use of the ODC in the mixture. However, the manufacturer or importer may elect to treat the sale or use of the mixture as the first sale or use of the ODC in the mixture.

Post-1989 ODCs (the 1990 election).

If this election is made, the tax on the post-1989 ODCs (listed earlier) contained in the mixture is imposed on the date of sale or use of the mixture. To make the election, check the first box in Part IV, under Elections. This election may be revoked only with the consent of the IRS.

Post-1990 ODCs (the 1991 election).

If this election is made, the tax on the post-1990 ODCs (listed earlier) contained in the mixture is imposed on the date of sale or use of the mixture. To make the election, check the second box in Part IV, under Elections. This election may be revoked only with the consent of the IRS.

Column (c).

Enter the tax per pound using the chart earlier.

Part V. ODC Tax on Imported Products, IRS No. 19

An imported taxable product is any product entered into the United States for consumption, use, or warehousing if any ODC was used as a material in the manufacture or production of the product. The product must also be listed in the imported products table issued by the IRS. See Regulations section 52.4682-3(f)(6). The tax is based on the weight of ODCs used in the manufacture of the product. If the weight can’t be determined under the exact method or table method (see below), the tax is 1% of the entry value of the product (value method).

Importer election.

Generally, an imported taxable product is taxed when sold or used by the importer. However, an importer may elect to treat the entry of products into the United States as the use of such products. This election applies to all products held by the importer when the election becomes effective, and all products the importer enters into the United States after the election becomes effective. If an election applies to an imported taxable product, tax is imposed on the product on the date of entry. To make the election, check the box in Part V, under Elections. This election may be revoked only with the consent of the IRS.

Figure the ODC Weight of the Product as Follows

Exact method.

If you determine the weight of each ODC used as a material in the manufacture of the product and you can support this determination, the ODC weight is the weight you determine.

Table method.

If you don’t use the exact method and the ODC weight is listed in the imported products table, use the ODC weight listed to figure the tax. See Pub. 510 for more information.

Follow the steps, next, to figure the tax for Part V, lines 1 through 3.

Column (a).

Enter the imported product and the applicable ODC. Use additional lines if there is more than one ODC.

Column (b).

Enter the number of taxable products imported.

Column (c).

Enter the ODC weight of the product in pounds. If you are using the value method, don’t complete this column.

Column (d).

Enter the tax per pound from the chart in the instructions for Part IV, earlier. If you are using the value method, enter 1% (0.01).

Column (e).

If you are using the value method to figure the tax, enter the entry value of the total number of imported products.

Column (f).

Figure the tax due by multiplying the number of products in column (b) by the ODC weight in column (c) by the tax per pound in column (d). If you are using the value method, multiply the 1% (0.01) rate in column (d) by the entry value in column (e).

Part VI. Tax on Floor Stocks of ODCs

Tax on floor stocks.

The floor stocks tax is imposed on the following ODCs.

Caution:

The tax per pound rates above are figured using the ozone-depletion factor. Do not multiply the tax per pound by the ozone-depletion factor.

For 2026.

You’re liable for the floor stocks tax if, on January 1, you hold any of the following.

1. At least 400 pounds of ODCs, other than halons or methyl chloroform, subject to the floor stocks tax.

2. At least 50 pounds of halons.

3. At least 1,000 pounds of methyl chloroform.

Report the tax on Form 6627 and Form 720 for the second calendar quarter of 2026. Payment of the tax is due by June 30, 2026.

Column (c).

Enter the tax per pound using the chart above.

Table of Taxable Imported Chemical Substances