A receivables desk built to be run by AI agents

request

curl -X POST https://www.duebay.com/api/v1/late-fee \
  -H "Authorization: Bearer dc_test_sandbox" \
  -H "Content-Type: application/json" \
  -d '{"balance_cents":250000,"due_date":"2026-06-01","as_of":"2026-07-15","state":"CA","terms":{"type":"percent_monthly","value":1.5,"grace_days":5}}'

response 200

{
  "data": {
    "fee_cents": 4839,
    "fee": 48.39,
    "basis": "ok",
    "days_overdue": 44,
    "chargeable_days": 39,
    "derivation": [
      "Invoice was due Jun 1, 2026; as of Jul 15, 2026 it is 44 days overdue.",
      "Minus the 5-day grace period agreed on the invoice: 39 chargeable days.",
      "Agreed rate: 1.5% per month, accrued per calendar month (not annualized to a daily rate).",
      "Chargeable period Jun 6, 2026 to Jul 15, 2026 = 1 full month + 9 days of a 31-day month = 1.2903 months.",
      "$2,500.00 x 1.5% x 1.2903 months = $48.39 (simple interest, not compounded).",
      "California law on agreed rates: Yes, subject to the constitutional usury limits of art. XV, § 1: for loans/forbearances NOT primarily for personal, family, or household purposes (i.e., business/commercial), the cap is the higher of 10% per annum or 5% over the Federal Reserve Bank of San Francisco discount rate (set as of the 25th day before the loan); consumer-purpose loans are capped at 10%. Exemptions swallow much of the rule: banks, savings associations, credit unions, industrial loan companies, licensed pawnbrokers, real-estate-broker-arranged loans secured by realty, and other statutorily exempt classes are not subject to the caps. Note usury law applies to loans/forbearances - bona fide trade credit and agreed charges on sales invoices are generally analyzed as forbearance only if credit is extended on an overdue debt. (Cal. Const. art. XV, § 1). Check your agreed rate against this before charging."
    ],
    "statute": {
      "state_code": "CA",
      "state_name": "California",
      "legal_interest_rate_pct": 10,
      "interest_rate_citation": "Cal. Civ. Code § 3289(b); Cal. Const. art. XV, § 1",
      "interest_rate_summary": "For breach of contract - the situation covering overdue B2B invoices - Civ. Code § 3289(b) provides that if a contract entered into after Jan. 1, 1986 does not stipulate a rate, the obligation bears interest at 10% per annum after breach (excludes notes secured by real-property deeds of trust); a contractually stipulated lawful rate keeps running after breach (§ 3289(a)). Separately, the constitutional default \"legal rate\" for loans/forbearances generally is 7% per annum (art. XV, § 1). Both verified on the official leginfo.legislature.ca.gov site.",
      "contract_rate_summary": "Yes, subject to the constitutional usury limits of art. XV, § 1: for loans/forbearances NOT primarily for personal, family, or household purposes (i.e., business/commercial), the cap is the higher of 10% per annum or 5% over the Federal Reserve Bank of San Francisco discount rate (set as of the 25th day before the loan); consumer-purpose loans are capped at 10%. Exemptions swallow much of the rule: banks, savings associations, credit unions, industrial loan companies, licensed pawnbrokers, real-estate-broker-arranged loans secured by realty, and other statutorily exempt classes are not subject to the caps. Note usury law applies to loans/forbearances - bona fide trade credit and agreed charges on sales invoices are generally analyzed as forbearance only if credit is extended on an overdue debt.",
      "contract_rate_citation": "Cal. Const. art. XV, § 1",
      "prompt_payment_scope": "public+private-construction",
      "prompt_payment_rate_summary": "Public: California Prompt Payment Act (Gov. Code § 927 et seq.) - state agencies must pay undisputed invoices within 45 days of receipt or pay late-payment penalties (must dispute within 15 working days; enhanced penalties for small businesses). Private construction: Civ. Code § 8800 - owner must pay undisputed progress payments within 30 days of demand; violation carries a penalty of 2% per month on the amount wrongfully withheld in lieu of interest, plus prevailing-party attorney fees; owner may withhold up to 150% of a good-faith disputed amount. Related contractor-to-subcontractor prompt-pay provisions exist across the construction codes. No general private non-construction commercial prompt-pay act.",
      "prompt_payment_citation": "Cal. Gov. Code § 927 et seq.; Cal. Civ. Code § 8800",
      "late_fee_notes": "Flat late fees on commercial invoices are enforceable if they satisfy California's liquidated-damages doctrine (reasonable, not a penalty; California law presumptively favors liquidated-damages clauses in non-consumer contracts). In construction, the 2%/month prompt-payment penalty regime supplies the remedy for wrongful withholding. Interest-style late charges on trade credit can implicate usury as a \"forbearance\" if the transaction is recharacterized as a loan - the business-purpose cap (higher of 10% or FRBSF discount +5%) is the relevant ceiling for non-exempt creditors.",
      "sources": [
        "https://leginfo.legislature.ca.gov/faces/codes_displaySection.xhtml?lawCode=CIV&sectionNum=3289",
        "https://leginfo.legislature.ca.gov/faces/codes_displayText.xhtml?lawCode=CONS&article=XV",
        "https://calconstructionlawblog.com/2013/07/09/an-overview-of-californias-prompt-payment-laws/",
        "https://www.levelset.com/prompt-payment/california-prompt-payment-faqs/",
        "https://law.justia.com/codes/california/2010/civ/8800-8802.html"
      ],
      "confidence": "high"
    },
    "balance_cents": 250000,
    "due_date": "2026-06-01",
    "as_of": "2026-07-15",
    "terms": {
      "type": "percent_monthly",
      "value": 1.5,
      "grace_days": 5
    },
    "statute_disclaimer": "Informational summary of state and federal statutes as researched on the sources listed per entry; not legal advice - verify current law with licensed counsel before relying on any rate or citation."
  },
  "request_id": "req_1f2e3d4c5b6a79880911aabb",
  "disclaimer": "Duebay computes late fees and interest from state statutes and the terms on your invoice, and shows the citation behind every number. It is general information, not legal advice: statutes change and contracts vary, so confirm with counsel before relying on a figure in a dispute. Where a rule could not be verified, Duebay says \"verify with counsel\" rather than guessing."
}