Comparison · verified July 2026
The Form 8621 Calculator is the deepest tool for one form. It just doesn't prepare the rest of your return.
This comparison treats Expat Tax Tools' Form 8621 Calculator as a specialist calculator rather than a full tax-return workflow. Its current export completeness, filing support, and pricing are not verifiable from the Atamatax codebase; confirm those details directly with the provider before deciding.
Who the Form 8621 Calculator is for
It is built for tax professionals and confident DIY filers who will assemble the 1040, FBAR, Form 8938 and treaty forms themselves and just want an audit-ready engine for the PFIC piece. If you file many Form 8621s across clients, its per-form pricing scales down further than anything else on the market.
Where each sits
Products in different categories are not better or worse than each other; they are for different returns. The category that matches your situation is the one to compare inside.
the Form 8621 Calculator
Complex foreign-investment workflow
Import the foreign portfolio, identify the PFICs, compute the allocation per holding and per year, reconstruct missing basis, and produce the workpapers.
Atamatax
Complex foreign-investment workflow
Import the foreign portfolio, identify the PFICs, compute the allocation per holding and per year, reconstruct missing basis, and produce the workpapers.
Professional handoff
The analysis packaged for an accountant to file from — classification with its reason, worksheets per holding, threshold arithmetic, an assumption log.
Self-serve tax software
You enter the figures and file the return yourself; the software computes the forms it supports.
Side-by-side
What you actually get
- Atamatax
- A complete US expat return: 1040 with Forms 2555 / 1116 / 8938, the FBAR, and Form 8621 for each PFIC.
- the Form 8621 Calculator
- Form 8621 only — a calculator that produces the one form, not a return.
Form 8621 depth (§1291 / QEF / MTM)
- Atamatax
- §1291 worksheet with real IRS quarterly interest rates; QEF and mark-to-market elections.
- the Form 8621 Calculator
- Dedicated multi-year PFIC engine, including transitional and expatriation rules — its whole product.
Price for a single PFIC
- Atamatax
- $499 flat — the entire return, with up to 25 Forms 8621 included (the $299 Simple package carries no PFICs).
- the Form 8621 Calculator
- ≈$59.40/yr to use it + $74.95 per form pay-as-you-go — the 8621 only; you still prepare the return.
Per-form cost at volume (preparers)
- Atamatax
- Flat per-return pricing; not sold per form.
- the Form 8621 Calculator
- Bundles fall to ~$10.95 per form at 500 — the cheapest per-form option anywhere.
FBAR + Form 8938
- Atamatax
- Generated alongside the 1040 package.
- the Form 8621 Calculator
- Out of scope — not produced.
FEIE / FTC / treaty (2555 / 1116 / 8833)
- Atamatax
- Handled as part of the return.
- the Form 8621 Calculator
- Out of scope — Form 8621 only.
Free draft before you pay
- Atamatax
- On-screen draft is free; you pay to generate the PDF package.
- the Form 8621 Calculator
- Annual subscription required before you can use the calculator.
Filing / e-file
- Atamatax
- Reviewable PDF package with step-by-step filing instructions; you file it.
- the Form 8621 Calculator
- Verify current PDF completeness and filing support with the provider.
Each row states what the two products do as of September 2026. We update this page when their offering changes — tell us if it's out of date.
Two Atamatax product lines appear in this table. Self-serve software for one tax year — $299 (no PFICs), $499 (up to 25 Forms 8621) and $799 (treaty positions) — and the Streamlined catch-up preparation tiers at $1,590–$2,990+, which are quoted in writing after a free scope check and prepared with you. They are different services at different prices.
Bottom line
Atamatax combines supported PFIC calculations and Form 8621 draft PDFs with mapped 1040, FBAR, Form 8938, and treaty worksheets in one paid package. You or your CPA still review and complete the forms and file outside Atamatax. Verify the other provider's current output and pricing directly.
Before choosing either
Check the facts the price depends on
- Is my fund a PFIC?Screens a fund or ETF by ISIN or domicile — the count of PFICs is what a per-form price turns on.Free · no signup
- PFIC filing cost calculatorWhat Form 8621 preparation is likely to cost from your holdings and years, to set beside a per-form quote.Free · no signup
- US expat tax calculatorWhich forms your year actually needs, and an outlook on the tax — the list the price on either side should be quoted against.Free · no signup
How this comparison was made
- Competitor facts come from the Form 8621 Calculator's own published pages — the price list, the plan descriptions, the forms list — and are linked under Sources where a public page exists. Where a price is quoted per case, the table says so rather than guessing a number.
- the Form 8621 Calculator publishes its pricing per engagement rather than as a list, so the table describes the model and quotes no figure.
- Atamatax's prices are rendered from the pricing configuration the checkout uses, so the table cannot show a price the product does not charge.
- Rows describe scope, not quality: no cell is marked as a winner, and the bottom line says who is better served by the other product.
Out of date? Tell us and the row is re-read. Atamatax pricing · Comparison methodology and index
Sources
Compare on your own situation
Which Atamatax package would your return actually need?
A few questions name the forms, the package and the price for your year — then the comparison above is about you, not about a generic expat.
Or skip the questions: the on-screen draft is free and you pay when you generate the package — start my return.