Form 6627 Instructions in Plain English
Form 6627, Environmental Taxes, is where you do the math for several unrelated-looking taxes, then carry each result to Form 720. Refineries, chemical makers, importers, and anyone holding certain ozone-depleting chemicals may all meet it. The January 2026 instructions organize it into six parts, each tied to specific IRS numbers. This guide reads through them in plain English, so you can skip straight to your part. If you make or import chemicals, also see our Superfund chemical tax page.
Form 6627 parts at a glance
| Part | Tax | IRS No. | Who files | Where the 2026 rate comes from |
|---|---|---|---|---|
| I | Domestic crude oil; imported petroleum products | 53; 16 | Refinery operators, users of crude oil before tax is imposed, and those entering products | $0.18 per barrel |
| II | Chemicals other than ozone-depleting chemicals | 54 | Manufacturers, producers, or importers who sell or use them | Listed on Form 6627, Part II |
| III | Imported chemical substances | 17 | Importers who sell or use them | Figured by conversion factor, or IRS table, or 10% of entry value |
| IV | Ozone-depleting chemicals (ODCs) | 98 | Manufacturers or importers who sell or use them | Per-pound chart in the instructions, such as CFC-11 at $19.30 |
| V | ODC tax on imported products | 19 | Importers of taxable products who sell or use them | ODC weight times the Part IV chart, or 1% of entry value |
| VI | Floor stocks of ODCs | 20 | Holders on January 1, other than the manufacturer or importer | Per-pound chart in the instructions, such as CFC-11 at $0.45 |
Part I: petroleum, and the oil spill change
Two oil spill taxes, IRS Nos. 18 and 21, expired after December 31, 2025. The instructions say not to use those lines unless Congress extends the taxes. What remains in 2026 is the petroleum Superfund rate of $0.18 per barrel, the same for both types. Domestic crude goes on IRS No. 53, and imported products go on IRS No. 16.
- Crude oil is taxed when received at a U.S. refinery, and the operator is liable. It includes crude oil condensates and natural gasoline.
- A user of crude oil is liable if domestic crude is used before reaching a refinery. Crude used to extract oil or natural gas on the premises where it was produced isn't taxable.
- Imported petroleum products are taxed when entered for use, consumption, or warehousing. The tax is imposed only once on an imported product, and the enterer must provide documentation to the refinery operator on request.
Fractional barrels are taxed proportionately using gallons over 42. As a made-up example, 10,000 whole barrels at $0.18 is $1,800.00. A further 21 gallons is 21/42 of a barrel, so $0.09 more. The total is $1,800.09.
Parts II and III: chemicals and imported substances
The instructions don't give Part II its own section, because the rates for taxable chemicals are printed on Form 6627, Part II itself. Use the form for that list and those rates.
Part III is more involved. The tax on an imported substance equals the chemical tax that would apply if it had been made in the United States. You choose a route based on what you know about it:
Choosing a Part III method
| What you know | Method | Column (f) math |
|---|---|---|
| The weight ratio of each taxable chemical (the conversion factor) | Conversion factor | Tons (b) times factor (d) times Part II rate (e), for each chemical |
| Not enough for a factor, but the IRS has a rate | IRS-provided rate | Tons (b) times rate (e) |
| Not enough for a factor, and no IRS rate yet | 10% of value | Appraised entry value (d) times 10% (e) |
The instructions also remind taxpayers that they may calculate their own rates, whether or not the IRS has provided one. The full substance table is in the instructions, and our Superfund chemical tax overview explains how these two taxes work in practice.
Parts IV, V, and VI: ozone-depleting chemicals
The per-pound charts already reflect the ozone-depletion factor. The instructions warn against multiplying by that factor again, in both Part IV and Part VI.
- Part IV uses the 2026 chart. Two mixture elections are made by checking boxes in Part IV, and each can be revoked only with IRS consent.
- Part V figures the weight of ODCs in an imported product by the exact method or the table method. If neither works, the tax is 1% of the product's entry value. An importer can elect to treat entry into the United States as use, by checking a box in Part V.
- Part VI is an annual inventory tax with its own thresholds and timing, including a June 30 payment date.
The instructions carry the full per-pound charts and the floor stocks thresholds. One detail to watch when you cross over to Form 720: the Form 720 instructions tell you to enter "column (d) of Form 6627, Part IV, line 4" on the line for IRS No. 20, while the January 2026 Form 6627 instructions place floor stocks in Part VI. Follow the part labeled floor stocks on the form you're using.
Carrying Form 6627 totals to Form 720
Attach Form 6627 and any continuation sheets to Form 720, and enter each total on its line. IRS Nos. 53, 16, 54, 17, 98, and 19 are in Part I of Form 720. IRS No. 20 is in Part II.
If you e-file, the IRS business rules enforce the match. Rules such as F720-003-01 (IRS No. 98), F720-212 (No. 54), F720-213 (No. 17), and F720-214 (No. 53) reject a return when a non-zero Form 720 amount doesn't equal the matching Form 6627 total. Other rules check Form 6627's own totals and multiplication.
Since these are mostly Part I taxes, deposits generally apply. No deposit is needed if net Part I liability doesn't exceed $2,500 for the quarter. If you later need a credit, Schedule C has references for chemicals (CRN 454), imported substances (317), ODCs (398), and ODCs in imported products (349).
Filing once your Form 6627 figures are ready
Work out your tons, barrels, or pounds first. Then you can file Form 720 online with EasyFile720, an IRS-authorized e-file provider covering Part I and Part II categories plus Schedules A and C. You enter your figures, the math is calculated, and validations catch common mistakes before you submit. An account is free with no credit card, and you pay $39.95 when you file, or use a Full Year Plan if you file every quarter. See our pricing or the steps for e-filing your quarterly return.
FAQ
Is Form 6627 filed by itself?▼
No. Form 6627 is attached to Form 720, along with any continuation sheets. The Instructions for Form 720 explain when and where to file.
Should I still fill in the oil spill lines for 2026?▼
No. The instructions say not to enter the expired taxes on the lines for IRS Nos. 18 and 21 unless Congress extends them, and to check IRS.gov/Form6627 for any extension.
Which revision do I use for 2026?▼
The instructions say filers should use the January 2026 revision of Form 6627 to report their tax.
Do government or nonprofit buyers escape these taxes?▼
Pub. 510 says no one is exempt from the environmental taxes, including the federal government, state and local governments, Indian tribal governments, and nonprofit educational organizations.
File Form 720 online
Create a free account with no credit card and build your return. You pay $39.95 only when you file. EasyFile720 is an IRS-authorized e-file provider, and you get an acknowledgment when the IRS accepts your return.
Sources: Instructions for Form 6627 (Rev. January 2026); Instructions for Form 720 (Rev. June 2026); Form 720 (Rev. June 2026); Pub. 510 (Rev. December 2025); IRS Form 720 Business Rules Publication 2026Q4 v1.0. General information, not tax advice. Confirm how the rules apply to you with a qualified advisor or the IRS.
