Section 1291 Form 8621 Calculation Guide
PFIC Calculator (8621calculator.com) — Section 1291 Form 8621 User Guide
This guide is for PFIC holdings reported under the default excess-distribution rules of IRC §1291. It walks through how to prepare the CSV file, upload and classify transactions, configure settings, run the Section 1291 calculation, and download the Excel workpapers for Form 8621.
1. Who Should Use This Section 1291 Guide
Use this guide if:
- The PFIC has no MTM (§1296) or QEF election, and you are filing under the default §1291 regime.
- You need to compute excess distributions, disposition gain, and §6621 interest across multiple years.
- You are reconstructing historic §1291 years, including years prior to a late QEF or MTM election.
If the PFIC is marketable stock and a timely MTM (§1296) election was made, please use the MTM (§1296) User Guide instead.
2. Prepare the CSV Transaction File (Sec 1291)
Prepare one CSV UTF-8 file per PFIC.
Do not combine multiple PFIC holdings in a single file — this calculator is designed to process only one PFIC at
a time.
Required columns (must match exactly):
- Date — YYYY-MM-DD (Excel Date Format Guide)
- Details — text only; must not contain commas, quotes, or line breaks
- Units — numeric only; no thousands separators
-
Value —
numeric only; no thousands separators or currency symbols
(Total amount in the original currency)
| Date | Details | Units | Value |
|---|---|---|---|
| 2020-03-05 | Contribution | 10000 | 15000 |
| 2020-03-17 | Buy | 7.059 | 112.53 |
| 2021-03-31 | Member Fee | -0.8363 | -1.95 |
| 2021-05-15 | Sold | -12.433 | -29.68 |
| 2022-03-12 | Reinvestment | 19.08384 | 22.83 |
Important rules for Section 1291:
- The calculator does not store or remember any data — each run must include full historical PFIC transactions from the first acquisition up to the end of the tax year.
- All Sale / Disposition transactions must use a negative Units value. Any positive Units entry is interpreted as an increase in holdings.
- If the Units or Value fields are blank in your CSV, you must fill them with 0.
3. Upload File
Click the upload area or drag your CSV file into the box. After uploading, the panel on the right will switch to the Transaction Type Mapping section automatically.
Supported format: CSV (UTF-8 only). If you are starting from Excel, save the file as CSV before uploading.
4. Category Mapping
The calculator will attempt to auto-identify categories based on the Details column, but every row must be reviewed and confirmed.
Available categories:
- Purchase
- Distribution
- Reinvestment
- Sale
- Return of Capital
- Cost Base Adjustment
- Ignore (excluded from PFIC computation)
One-page classification summary (decision logic)
Use the rules below to choose the correct Type for each transaction. For Section 1291, accurate classification is essential for FIFO, excess distributions, and historic interest calculations.
| Units | Value | Description (what it says on the statement) | Type |
|---|---|---|---|
| > 0 | > 0 | Buy / Purchase / Subscription / Contribution | Purchase |
| > 0 | Any | DRIP / Reinvest / Reinvestment / Dividend reinvested | Reinvestment |
| < 0 | Any | Sell / Sale / Redemption / Switch-out | Sale |
| = 0 | > 0 | Dividend / Distribution / Interest | Distribution |
| = 0 | Any | ROC / Return of Capital | Return of Capital |
| = 0 | Any | Basis adjustment (e.g. prior-year QEF / MTM adjustment) | Cost Base Adjustment |
| Any | Any | Fees / Charges / NAV adjustment / Internal fund tax | Ignore |
Special Cases — “Ignore” and Manual Mapping View Ignore Guide →
Entries marked with
-- Select Type --
must be manually mapped.
All other auto-identified categories must be reviewed and confirmed
item by item — only accurate categorization will produce accurate calculations.
Any transaction marked as Ignore is excluded entirely from the calculator.
5. Configure Settings
Settings are displayed on the left panel of the calculator.
- Tax Year — must be selected.
- Currency — must be selected.
- Ownership % — percent held by the owner.
- Ending Balance — optional; used for Form 8621 Part I, Line 4.
- PFIC Start — normally the first acquisition year. Adjust only if the taxpayer became U.S. resident later.
- Method — will be shown as Section 1291.
- Distribution FTC — enter foreign tax withheld on distributions.
- 1248 FTC — rare; applies only to sales triggering §1248.
6. Run Section 1291 Calculation
Once all transaction categories are mapped, the green Run PFIC Calculation button will become enabled.
After confirming the tax year, currency, and all settings, click the button to start the Section 1291 lot-by-lot FIFO computation.
7. License Verification
After clicking Run PFIC Calculation, a license verification window will appear. You must enter your email and your license code.
If you don’t have a license code, click buy me a coffee ☕ to support the tool. Send the payment screenshot by email to receive a code within one business day.
8. Download Excel Results
When complete, a green Download Result Excel button will appear at the bottom-right. A blue link will also appear at the top-right.
The calculator does not store history. You must download the Excel file immediately after calculation. If refreshed, the file is lost.
9. Section 1291 Output Sheets & Sample Workpapers
A. Section 1291 Outputs
- CCH_8621_Input — ready for CCH Axcess / ProSystem fx.
- 16a_Summary — key computation data and holdings schedule.
- 16a_Disposition — FIFO disposition details, annual tax/interest breakdown.
- 16a_Excess_Distribution — per-block includible distributions with carry history.
- CCH_Upload — additional worksheet uploadable to CCH.
- 8621 Filing Example — Part I and Part V mock-up.
- Other IRS forms (1040, Sch D, 8949, 1116 etc.)
- PFIC_WS — all calculations including FX conversion.