Employee withholding elections

Detects completed employee tax withholding declarations and elections: ATO Tax file number declaration (NAT 3092) and withholding declaration (NAT 3093), US Form W-4 and UK starter checklist, with the payee identified and a TFN/SSN, residency or tax-free threshold answer, filing status or payer ABN.

Type: regex
Engine: boost_regex
Confidence: medium
Confidence justification: Medium: the primary phrases also appear in policies, guidance, blank forms and news, so enforce tiers require a populated person field and 85 adds a record-specific populated detail plus independent corroboration. Person values are customer-defined (employee IDs, position numbers), so the field regexes use labelled loose values with a placeholder guard. 85/75 are heuristic evidence tiers, not measured accuracy.
Detection quality: Topic false positive
Jurisdictions: global
Regulations: Taxation Administration Act 1953 (Cth), Privacy Act 1988 (Cth), Information Privacy Act 2009 (Qld), NDB Scheme (Cth), GDPR
Frameworks: ISO 27001, ISO 27701
Data categories: financial, pii, employment
Scope: wide
Risk rating: 4
Platform compatibility: Purview: Compatible, GCP DLP: Compatible, Macie: Compatible, Zscaler: Compatible, Palo Alto: Degraded, Netskope: Unsupported

Pattern

(?i)\b(?:(?:TFN|tax\s+file\s+number)\s+declaration|withholding\s+declaration|NAT\s?309[23]|Form\s+W-4|employee(?:'s)?\s+withholding\s+(?:certificate|allowance\s+certificate|election)s?|withholding\s+elections?|starter\s+checklist)\b

Corroborative evidence keywords

payer, signature, Australian Taxation Office, ATO, IRS, HMRC, PAYG, residency, dependents, payroll

Proximity: 300 characters

Should match

Tax file number declaration (NAT 3092) Surname or family name: Teston First given name: Avery Tax file number: 123 456 782 Are you an Australian resident for tax purposes? Yes Do you want to claim the tax-free threshold from this payer? Yes Payer ABN: 51 824 753 556 — 85: Completed TFN declaration with TFN, residency and payer ABN
Form W-4 Employee's Withholding Certificate Employee name: Morgan Teston SSN: 123-45-6789 Filing status: Single Signed and returned to payroll for the IRS records. — 85: Completed W-4 with SSN and filing status
Withholding declaration Payee name: Jordan Staffson Variation to withholding lodged with payroll this week. — 75: Withholding declaration naming the payee, no TFN or answers

Should not match

Give a TFN declaration to your new payer. This fact sheet explains when to claim the tax-free threshold and how withholding works. — Fact sheet - must stay below 75
Tax file number declaration Surname or family name: __________ Tax file number: ___ ___ ___ Payer ABN: __________ — Blank form - must stay below 75
The ATO reminded employers in a media release that TFN declaration forms must be kept for 7 years. — News / media release - must stay below 75
unrelated generic text without domain phrases — No relevant topic phrases present
placeholder value 12345 — Random text should not match topic-specific regex
payroll reimbursement — Generic word pair from old broad template should not match

Known false positives

Policies, directives, fact sheets, guidance and training material that name the record type. Mitigation: Enforce tiers require a populated person field; guidance text has labels without values and guidance/training/media-release framing is excluded.
Blank forms, templates and HR system configuration. Mitigation: Blank lines, square- and angle-bracket placeholders, XXX and n/a/tbc values are rejected by the placeholder guard; template/fixture words are excluded.
Aggregate statistics and news reporting. Mitigation: No populated person field, so these stay at 65 discovery.
Records that identify the person only in free text (no field label) fall to 65. Mitigation: Accepted precision trade-off; extend the person-field regex with the customer employee-id format to recover recall.