{
  "title": "Flat-PDF field detection on a flattened IRS W-9 (Rev. March 2024)",
  "measured_on": "2026-09-08",
  "engine_version": "0.1.0",
  "source_pdf": "https://www.irs.gov/pub/irs-pdf/fw9.pdf",
  "source_sha256": "2d420cbb4123dcf1fb82595b2359cfbb5d81f00b9df9d359fcc7af361d093f53",
  "method": "Recorded the 23 AcroForm fields in the official interactive W-9, baked the widgets into the page content with PyMuPDF so the copy has no form fields (the state a print-to-PDF or sign-and-flatten step leaves it in), ran the pdfields detector on that copy, and matched each detection to an official field by IoU >= 0.3 on the same page. Produced by scripts/w9_flat_detection.py.",
  "summary": {
    "official_fields": 23,
    "official_by_type": {
      "text": 15,
      "checkbox": 8
    },
    "recovered": 12,
    "recovered_by_type": {
      "text": 4,
      "checkbox": 8
    },
    "missed": [
      "Line 2, business name",
      "Line 3a, LLC tax classification letter",
      "Line 3a, other (describe)",
      "Line 4, exempt payee code",
      "Line 5, address",
      "Requester's name and address",
      "Line 7, account numbers",
      "Part I, SSN first 3 digits",
      "Part I, SSN middle 2 digits",
      "Part I, EIN first 2 digits",
      "Part I, EIN last 7 digits"
    ],
    "detections_total": 32,
    "detections_by_page": {
      "1": 14,
      "2": 1,
      "3": 2,
      "4": 12,
      "5": 3
    },
    "extra_detections_page1": 2,
    "extra_detections_instruction_pages": 18,
    "tier_detected": "tier_2_flat_digital"
  },
  "fields": [
    {
      "field": "f1_01",
      "line": "Line 1, name",
      "official_type": "text",
      "recovered": true,
      "iou": 0.87,
      "detected_type": "text"
    },
    {
      "field": "f1_02",
      "line": "Line 2, business name",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "c1_1[0]",
      "line": "Line 3a, individual/sole proprietor box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.91,
      "detected_type": "checkbox"
    },
    {
      "field": "c1_1[1]",
      "line": "Line 3a, C corporation box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.86,
      "detected_type": "checkbox"
    },
    {
      "field": "c1_1[2]",
      "line": "Line 3a, S corporation box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.86,
      "detected_type": "checkbox"
    },
    {
      "field": "c1_1[3]",
      "line": "Line 3a, partnership box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.86,
      "detected_type": "checkbox"
    },
    {
      "field": "c1_1[4]",
      "line": "Line 3a, trust/estate box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.86,
      "detected_type": "checkbox"
    },
    {
      "field": "c1_1[5]",
      "line": "Line 3a, LLC box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.96,
      "detected_type": "checkbox"
    },
    {
      "field": "f1_03",
      "line": "Line 3a, LLC tax classification letter",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "c1_1[6]",
      "line": "Line 3a, other box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.96,
      "detected_type": "checkbox"
    },
    {
      "field": "f1_04",
      "line": "Line 3a, other (describe)",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "c1_2[0]",
      "line": "Line 3b, foreign partners/owners box",
      "official_type": "checkbox",
      "recovered": true,
      "iou": 0.86,
      "detected_type": "checkbox"
    },
    {
      "field": "f1_05",
      "line": "Line 4, exempt payee code",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "f1_06",
      "line": "Line 4, FATCA exemption code",
      "official_type": "text",
      "recovered": true,
      "iou": 0.73,
      "detected_type": "text"
    },
    {
      "field": "f1_07",
      "line": "Line 5, address",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "f1_08",
      "line": "Line 6, city, state, ZIP",
      "official_type": "text",
      "recovered": true,
      "iou": 0.56,
      "detected_type": "text"
    },
    {
      "field": "f1_09",
      "line": "Requester's name and address",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "f1_10",
      "line": "Line 7, account numbers",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "f1_11",
      "line": "Part I, SSN first 3 digits",
      "official_type": "text",
      "recovered": false,
      "iou": 0.05,
      "detected_type": null
    },
    {
      "field": "f1_12",
      "line": "Part I, SSN middle 2 digits",
      "official_type": "text",
      "recovered": false,
      "iou": 0.03,
      "detected_type": null
    },
    {
      "field": "f1_13",
      "line": "Part I, SSN last 4 digits",
      "official_type": "text",
      "recovered": true,
      "iou": 0.62,
      "detected_type": "text"
    },
    {
      "field": "f1_14",
      "line": "Part I, EIN first 2 digits",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    },
    {
      "field": "f1_15",
      "line": "Part I, EIN last 7 digits",
      "official_type": "text",
      "recovered": false,
      "iou": 0.0,
      "detected_type": null
    }
  ]
}