API Documentation

X-API-Key: YOUR_API_KEY

curl -X POST https://n8nsandbox.undtec.com/webhook/slapi/internal/v3/calculate \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "state": "California",
    "premium": 10000,
    "carrier_fees": 250,
    "lob": "SLT-PROP"
  }'

{
  "success": true,
  "state": "California",
  "calculation": {
    "premium": 10000,
    "breakdown": {
      "base_tax": {
        "rate": "3%",
        "amount": 307.5,
        "name": "Surplus Line Premium Tax",
        "source": "https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=INS&sectionNum=1775.5"
      },
      "stamping_fee": {
        "rate": "0.18%",
        "amount": 18.45,
        "name": "Stamping Fee",
        "source": "https://www.slacal.com/resources/broker-taxes-fees"
      }
    },
    "total_tax": 325.95,
    "total_due": 10575.95,
    "fees_taxable": 250,
    "fees_exempt": 0
  }
}

curl -X POST "https://n8nsandbox.undtec.com/webhook/slapi/internal/v3/calculate" \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "state": "California",
    "premium": 10000,
    "carrier_fees": 250,
    "lob": "SLT-PROP"
  }'

{
  "state": "California",
  "premium": 10000,
  "fees": 250,
  "carrier_fees": 250,
  "broker_fees": 0,
  "wholesaler_fees": 0,
  "fee_split_given": true,
  "fees_as_sent": 0,
  "conditions_met": {
    "carrier": false,
    "broker": false,
    "wholesaler": false
  },
  "lob": "SLT-PROP",
  "effective_date": null,
  "jurisdiction": null,
  "success": true,
  "rates_from": "current-v3",
  "useHistoricalRates": false,
  "stateData": {
    "state": "California",
    "state_code": "CA",
    "legislative_source": "https://www.slacal.com/resources/broker-taxes-fees",
    "effective_from": null,
    "effective_to": null,
    "data_source": "v3"
  },
  "calculation": {
    "premium": 10000,
    "breakdown": {
      "base_tax": {
        "rate": "3%",
        "amount": 307.5,
        "name": "Surplus Line Premium Tax",
        "source": "https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=INS&sectionNum=1775.5"
      },
      "stamping_fee": {
        "rate": "0.18%",
        "amount": 18.45,
        "name": "Stamping Fee",
        "source": "https://www.slacal.com/resources/broker-taxes-fees"
      }
    },
    "total_tax": 325.95,
    "total_due": 10575.95,
    "fees_taxable": 250,
    "fees_exempt": 0
  },
  "state_rules": {
    "rounding": {
      "applied": "cent",
      "rule": {
        "exists": "yes",
        "unit": "dollar",
        "when": "aggregate",
        "applies_to": [
          "premium",
          "tax",
          "fees",
          "total"
        ],
        "citation": "Cal. Dep't of Insurance Form FS-006, surplus line broker tax return instructions (2025 rev. 11)"
      }
    },
    "fee_cap": {
      "exists": "conditional",
      "amount": 250,
      "exceeded": false,
      "verified_against_transaction": false,
      "citation": "Cal. Ins. Code s 1764.1(a)(2), (b) notice para. 8, (d)(2) (amended Stats. 2019, Ch. 201, s 9); Cal. Ins. Code s 1623(a)(3); 10 CCR tit. 10, ss 2189.1, 2189.3, 2189.5(d)"
    },
    "both_fees_allowed": null,
    "commission_rules": null
  },
  "notes": [
    "Line of business: SLT-PROP (property)",
    "CA restricts what a broker may charge the insured (Cal. Ins. Code s 1764.1(a)(2), (b) notice para. 8, (d)(2) (amended Stats. 2019, Ch. 201, s 9); Cal. Ins. Code s 1623(a)(). Not verified against this transaction.",
    "carrier fee 250 is inside the taxable base (PRIMARY (broker side): letter of Dennis C. Ward, Chief, Enforcement Division, California Department of Insurance, to the)"
  ],
  "stamp": [
    {
      "instrument": "D1 signed at application",
      "ordinal": 1,
      "wording": "IMPORTANT NOTICE: 1. The insurance policy that you are applying to purchase is being issued by an insurer that is not licensed by the State of California. ... [abbreviated here; the API returns all 8 numbered paragraphs, about 2,500 characters]",
      "how_it_must_appear": "boldface 16-point type on a FREESTANDING document that the applicant SIGNS; the broker keeps the signed copy 5 years. Not required for a renewal with the same carrier, nor for an industrial insured (s 1764.1(c)).",
      "style": { "pt": 16, "bold": true },
      "citation": "D-1, signed at application. Cal. Ins. Code s 1764.1(b), leginfo.legislature.ca.gov, retrieved 2026-08-13.",
      "provenance": "state_first_party",
      "provenance_note": null,
      "verified_at": "2026-08-17"
    },
    {
      "instrument": "D2 affixed to policy",
      "ordinal": 2,
      "wording": "IMPORTANT NOTICE: 1. The insurance policy that you have purchased is being issued by an insurer that is not licensed by the State of California. ... [abbreviated here]",
      "how_it_must_appear": "boldface 16-point type, contained in or affixed to the FRONT of the policy or certificate. No signature.",
      "style": { "pt": 16, "bold": true },
      "citation": "D-2, affixed to the policy. Cal. Ins. Code s 1764.1(b), leginfo.legislature.ca.gov, retrieved 2026-08-13.",
      "provenance": "state_first_party",
      "provenance_note": null,
      "verified_at": "2026-08-17"
    }
  ]
}

curl -X POST https://n8nsandbox.undtec.com/webhook/slapi/internal/v3/calculate \
  -H "X-API-Key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "state": "California",
    "premium": 10000,
    "carrier_fees": 250,
    "lob": "SLT-PROP",
    "effective_date": "2022-06-01"
  }'

{
  "success": true,
  "state": "California",
  "effective_date": "2022-06-01",
  "rates_from": "historical",
  "calculation": {
    "premium": 10000,
    "breakdown": {
      "base_tax": {
        "rate": "3%",
        "amount": 307.5,
        "name": "Surplus Line Premium Tax",
        "source": "https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=INS&sectionNum=1775.5"
      },
      "stamping_fee": {
        "rate": "0.25%",
        "amount": 25.63,
        "name": "Stamping Fee",
        "source": "https://www.slacal.com/resources/2023-stamping-fee-decrease-procedures"
      }
    },
    "total_tax": 333.13,
    "total_due": 10583.13,
    "fees_taxable": 250,
    "fees_exempt": 0
  }
}

curl "https://n8nsandbox.undtec.com/webhook/sltax_history_list?state=Texas&date=2024-01-02" \
  -H "X-API-Key: YOUR_API_KEY"

{
  "success": true,
  "state": "Texas",
  "state_code": "TX",
  "effective_date": "2024-01-02",
  "rates_from": "historical",
  "charges": [
    {
      "key": "sl_tax",
      "name": "Surplus Lines Premium Tax",
      "rate": "4.85%",
      "basis": "percent",
      "source": "https://comptroller.texas.gov/taxes/insurance/surplus-lines.php",
      "effective_from": "2020-01-01"
    },
    {
      "key": "stamping_fee",
      "name": "Stamping Fee",
      "rate": "0.04%",
      "basis": "percent",
      "source": "https://www.sltx.org/brokers/billing-information/stamping-fees-taxes/",
      "effective_from": "2024-01-01"
    }
  ],
  "payment_frequency": null,
  "rounding_rule": "Whole dollars for premium, cents for the tax on the return total, not per policy. (Tex. Form 25-104 (printed column headings))",
  "legislative_source": "https://comptroller.texas.gov/taxes/insurance/surplus-lines.php",
  "earliest_verified": "2020-01-01",
  "account": {
    "balance": "9.62",
    "free_queries_remaining": 0,
    "was_free_query": false
  }
}

curl "https://n8nsandbox.undtec.com/webhook/sltax_history_list?state=Iowa&date=2025-06-15" \
  -H "X-API-Key: YOUR_API_KEY"

{
  "success": true,
  "state": "Iowa",
  "state_code": "IA",
  "effective_date": "2025-06-15",
  "rates_from": "historical",
  "charges": [
    {
      "key": "sl_tax",
      "name": "Premium Tax",
      "rate": "0.95%",
      "basis": "percent",
      "source": "https://www.legis.iowa.gov/docs/code/432.1.pdf",
      "effective_from": "2025-01-01"
    }
  ],
  "payment_frequency": null,
  "rounding_rule": null,
  "legislative_source": "https://www.legis.iowa.gov/docs/code/432.1.pdf",
  "earliest_verified": "2020-01-01",
  "account": {
    "balance": "9.62",
    "free_queries_remaining": 0,
    "was_free_query": false
  }
}

{
  "error": true,
  "code": "MISSING_STATE",
  "message": "state is required. Send a two-letter code or a full name.",
  "statusCode": 400
}

{
  "success": true,
  "state": "California",
  "calculation": {
    "premium": 10000,
    "breakdown": { "base_tax": { "rate": "3%", "amount": 307.50, "name": "Surplus Line Premium Tax", "source": "https://leginfo.legislature.ca.gov/..." } },
    "total_tax": 325.95,
    "total_due": 10575.95,
    "fees_taxable": 250,
    "fees_exempt": 0
  },
  "state_rules": { "rounding": { "applied": "cent", "rule": { "exists": "yes", "unit": "dollar", "when": "aggregate" } } },
  "notes": [ "carrier fee 250 is inside the taxable base (...)" ],
  "warnings": [],
  "lob": "SLT-PROP",
  "stamp": [
    {
      "instrument": "stamp",
      "ordinal": 1,
      "wording": "This insurance has been placed with an insurer that is not licensed by the state of Michigan...",
      "how_it_must_appear": "\"printed, typed, or stamped in RED INK upon its FACE, in not less than 10-point type\"",
      "style": { "pt": 10, "ink": "red" },
      "citation": "MCL 500.1922 (\"Notice on face of instrument evidencing surplus lines insurance\")",
      "provenance": "state_first_party",
      "provenance_note": null,
      "verified_at": "2026-08-14"
    }
  ]
}

{
  "error": true,
  "code": "FEE_TYPE_REQUIRED",
  "message": "CA taxes a fee differently depending on who charged it, so a total of 250 cannot be priced. Split it into carrier_fees, broker_fees or wholesaler_fees.",
  "statusCode": 400
}

{
  "error": true,
  "code": "FEE_TYPE_REQUIRED",
  "message": "CA taxes a fee differently depending on who charged it, so a total of 250 cannot be priced. Split it into carrier_fees (a policy, inspection, underwriting or filing fee the insurer required), broker_fees (your own charge for your own services, which you keep) and wholesaler_fees (a wholesaler or MGU's charge).",
  "statusCode": 400
}

{
  "error": true,
  "code": "NO_RATES_FOR_DATE",
  "message": "No surplus-lines rules are on file for CA effective 2019-01-01. Verified data for this state begins 2020-01-01.",
  "statusCode": 404
}

const response = await fetch('https://n8nsandbox.undtec.com/webhook/slapi/internal/v3/calculate', {
  method: 'POST',
  headers: {
    'X-API-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({
    state: 'California',
    premium: 25000,
    lob: 'SLT-PROP'
  })
});
const result = await response.json();
console.log(`Total: $${result.total_due.toLocaleString()}`);

import requests

headers = {
    'X-API-Key': 'YOUR_API_KEY',
    'Content-Type': 'application/json'
}
payload = {
    'state': 'Texas',
    'premium': 50000,
    'lob': 'SLT-PROP'
}
response = requests.post('https://n8nsandbox.undtec.com/webhook/slapi/internal/v3/calculate',
                         json=payload, headers=headers)
result = response.json()
print(f"Total with taxes: ${result['total_due']:,.2f}")