Schedule K-1 (Form 1065), box 15
Box 15: Credits
Tax credits passed through from the partnership, each with a code letter. Many go through Form 3800 or a form of their own.
What box 15 reports
Credits the partnership generated or passed through to you, one line per credit with a code letter and an amount.
Some codes are amounts you enter, others are only a signal that you need a specific form.
Where it goes on your return
Depends on the code
The common case
Each credit code names its own form. For example, the low-income housing credit and the credit for increasing research activities each have a form of their own, and many credits then flow to Form 3800, General Business Credit.
When it depends on you
Credits are often limited by tax liability and by passive rules. See the Partner's Instructions for the credit code you have.
Common codes in box 15
| Code | Title | Goes to |
|---|---|---|
| C | Low-income housing credit (2025 list) | See the Partner's Instructions |
| D | Low-income housing credit (2025 list) | See the Partner's Instructions |
| E | Qualified rehabilitation expenditures (rental real estate) | See the Partner's Instructions |
| F | Other rental real estate credits | See the Partner's Instructions |
| G | Other rental credits | See the Partner's Instructions |
| M | Credit for increasing research activities | See the Partner's Instructions |
| O | Backup withholding | See the Partner's Instructions |
| ZZ | Other | See the Partner's Instructions |
There are dozens of credit codes and the first letters have been renumbered in recent years. Only a few are shown here. Code letters and titles change between tax years: new codes are added and old ones are retired. This list is the 2025 list. K1 FastTax reads and exports only the code letter and the amount, so check the letter against the instructions for the year printed on your K-1 and against the partnership's attached statement.
A real example line
Below, a line written the way the document text arrives, run through the same reader as your upload. The reader matches the box number and the IRS label, then reads the amount, so it still finds the line when the scan is noisy.
| Line as the engine reads it | Box | Recorded value | Status |
|---|---|---|---|
15 Credits F 1,800 | 15 | F 1,800 | Read |
Check before you enter it
- A credit line is often blank. When it is not, expect an extra form and likely your preparer's help.
In the K1 FastTax output
CSV column: box_15_codes. In the checklist a line looks like Schedule K-1 (1065) screen, box 15, code A. All CSV columns.
Official source
The IRS text for every box is in the Partner’s Instructions for Schedule K-1 (Form 1065). Use the edition for the tax year printed on your K-1, because box wording and code lists change.
Plain answers
Questions about box 15
Where do the credits in box 15 go on my return?
Each credit code names its own form. For example, the low-income housing credit and the credit for increasing research activities each have a form of their own, and many credits then flow to Form 3800, General Business Credit. See the Partner's Instructions for the code you have.
Why is box 15 empty on my K-1?
Box 15 is often blank: the partnership had no credits to pass through to you. K1 FastTax leaves the cell empty and lists the box as blank in the checklist, so you know there is nothing to enter.
Box 15 has a code I do not recognise. What do I do?
Some codes are amounts you enter and others are only a signal that you need a specific form. There are dozens of credit codes, so look the letter up in the Partner's Instructions for the year on your K-1. Expect an extra form, and ask your preparer for help if you are not sure.
Can I use the full credit shown in box 15?
Not necessarily. Credits are often limited by your tax liability and by the passive activity rules, and some carry forward. See the Partner's Instructions for the credit code you have and the instructions for the form it names.
Box 15 shows STMT. What do I enter?
STMT means the amount is on a statement attached to the K-1. Read the statement for the amount and the credit details. K1 FastTax records STMT in the CSV and adds the line to the review list, but it does not read the statement.
Which CSV column holds box 15?
Credits go into the box_15_codes cell as code and amount pairs separated by semicolons. The plain box_15 column stays empty for coded boxes, and a blank box 15 is an empty cell, not a zero.
Is box 15 the same on a Form 1120-S or Form 1041 K-1?
Credits are box 13 on both a Form 1120-S K-1 and a Form 1041 K-1. The credit codes differ between forms, so use the instructions for the form in front of you.
Related boxes
Read box 15 from your own K-1
Free: 1 file per day, up to 10 pages, no account. Nothing is filed and nothing is entered into tax software for you.