Synthetic examples

Practice extracting UK investment records and checking PFIC calculations without using anyone’s real financial information.

← Return to the walkthrough

Choose the test you want

1. Broker-document test

Use fictional CSV exports, quarterly statements, contract notes, and notices to build a normalized transaction and holdings ledger. A hash-bound reviewed mapping is included for a quick non-blind smoke test.

Download pack Sample statement

2. PFIC calculation test

Use six candidate section 1291 cases to compare arithmetic, holding-period allocations, and proposed Form 8621 fields.

Download cases Sample case

Run a blind broker-document test

  1. Give the tester only broker_exports, statements, contract_notes, and notices.
  2. Ask for source-linked normalized transactions and December 31 positions.
  3. Do not reveal source_truth or expected until the extraction is complete.
  4. Compare every row and holding with the answer key, then investigate differences.
  5. The optional ambiguous switch should remain unresolved rather than being guessed.

Reference-case status

The PFIC cases are candidate examples, not “correct filed returns.” They are deterministic and internally tested, but remain CANDIDATE_UNREVIEWED. There is no budget or plan to commission paid professional validation. Contributors can help by independently reproducing a case, publishing their method, and documenting disagreements. Professional review is optional if a qualified collaborator volunteers or future funding becomes available.

See the included volunteer validation guide for the review steps and status labels.

Primary sources: Form 8621 (December 2025) and the IRS instructions.