Guide  ·  Form 3800

Every credit passes through one form.

Form 3800, the General Business Credit, applies the Section 38 limitation and carries the federal R&D tax credit (Section 41) to the return. Partnerships and S corporations skip it. Everyone else files it, including the partner or shareholder who receives the credit on a K-1.

Part III, line 1cholds the research credit from Form 6765. An eligible small business uses line 4i.
Column (c)carries the EIN of the partnership, S corporation, estate, or trust that passed the credit through.
Line 38is the credit allowed for the year, and the form names the return line it goes to.

Where the credit lands

Form 3800 (2025), Part III
FilerPart III lineColumns to complete
Most corporations, individuals, estates, and trustsLine 1c, Form 6765Column (d) if the credit is subject to the passive activity limit, otherwise column (e). Column (c) holds the pass-through entity EIN when the credit came on a K-1.
Eligible small businessLine 4i, Form 6765 (ESB)Same columns. An eligible small business is a non-publicly traded corporation, a partnership, or a sole proprietorship with average annual gross receipts of $50 million or less for the three prior years.
Partnerships and S corporationsNot filed for this creditThe entity reports line 30 of Form 6765 on Schedule K. Each owner files Form 3800.

From Part III to the return

Form 3800, Part II, line 38
  1. Part III collects each current year credit by source form. More than one pass-through source on a line means column (a) counts them and Part V lists them.
  2. Parts I and II apply the general business credit limitation. The credit can't cut tax below the greater of the tentative minimum tax or 25 percent of net income tax above $25,000. For a corporation outside the corporate minimum tax, that means the credit can offset all tax up to $25,000 and 75 percent of the tax above it.
  3. Part II, line 38 is the credit allowed for the year. The form itself names the destination: Schedule 3 (Form 1040), line 6a; Form 1120, Schedule J, line 5c; Form 1041, Schedule G, line 2b.
  4. Unused credit carries back one year and forward twenty. Carryforwards come back in a later year through Part IV, on the line for that credit.

Common questions

Does a K-1 recipient attach Form 6765 to Form 3800?

Not when the recipient has no research of their own. The K-1 amount goes on Part III, line 1c, or line 4i when both the entity and the recipient are eligible small businesses, with the entity EIN in column (c). See the Form 6765 guide for the case where the recipient also computes a credit.

Which column, (d) or (e)?

Column (d) holds credits from a passive activity before the passive limit. Form 8582-CR or Form 8810 then figures how much is allowed, and that amount goes on Part I, line 3. A credit from a business the owner materially participates in goes in column (e).

Can the credit reduce tax to zero?

Not for a corporation with net income tax above $25,000. The limitation in Part II leaves 25 percent of the tax above that threshold in place, and the rest of the credit carries back one year or forward twenty.

Sources

Related guides

  • Form 6765Completing Form 6765, the credit form itself.
  • Form 1120C corporations: Schedule J, Section 174A, and Form 1120-X.
  • Form 1120-SS corporations: Schedule K line 13g, K-1 box 13 code M, and the shareholder.
  • Form 1065Partnerships: Schedule K line 15f, K-1 box 15 code M, and the partner.
  • Form 1040Individuals: Schedule 3 line 6a, Schedule C, and Form 1040-X.
  • Form 1041Estates and trusts: Schedule G line 2b and K-1 box 13 code I.

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