Build a State Sales & Use Tax Return Dataset

Skill: Convert sales data into a multi-jurisdiction state sales/use tax return dataset

Region: United States Category: Sales & Use Tax — state/local return Does: Takes a period's sales data and produces a state sales & use tax return dataset (JSON) with gross/taxable/exempt sales and tax due broken out by state, county, city, and special district — ready to key into a state DOR portal or a Streamlined (SST) simplified electronic return. Standard: State DOR sales/use tax return (jurisdiction-specific; SUT/STR). Worked example models a home-rule, destination-sourced state.

Sales-tax rules are jurisdiction-specific and change frequently (rates, thresholds, taxability, sourcing). The AI computes from the rates and taxability you supply or that it is instructed to look up; always confirm current rates and nexus rules with the state DOR or your tax engine before filing. Economic-nexus thresholds derive from South Dakota v. Wayfair.

When this applies

• A seller files a periodic state sales/use tax return and must allocate tax to local jurisdictions (destination sourcing).
• Covers marketplace-facilitator deductions, exempt/resale sales, and use tax self-assessed on taxable purchases where sales tax was not charged.
• Not a single national format — each state DOR differs; this produces a normalized dataset that maps onto the state's return lines or an SST simplified return.

Conversion procedure

1. Read the source. Accept CSV/JSON of transactions (date, ship-to jurisdiction, amount, tax collected, exemption reason, channel) plus a rate/taxability table. Identify the filing state and period.
2. Determine nexus. Confirm the seller has nexus (physical or economic — e.g. >$100k sales or 200 transactions, state-specific). Flag if below threshold.
3. Classify each sale. Taxable, exempt (resale/exemption certificate), or marketplace-facilitated (collected by the marketplace → deductible from the seller's taxable base).
4. Allocate by jurisdiction. Assign each taxable sale to state + county + city + special district by the ship-to address; stack the local rates.
5. Compute gross sales, deductions, taxable sales, and tax per jurisdiction; sum to the return total; apply any timely-filing discount.
6. Emit the JSON dataset; validate with the checklist.

Source → return field map

Document structure

sales_use_tax_return
├── filer            (name, state tax id)
├── state, period
├── gross_sales
├── deductions       (marketplace_facilitator, exempt_resale, other)
├── taxable_sales
├── jurisdictions[]  (code, level, rate, taxable, tax)
├── use_tax_due
├── total_tax_due
├── vendor_discount
└── net_due

Code tables

Jurisdiction level

Common deduction reasons

Calculation rules

• Taxable sales = gross_sales − Σ deductions.
• Combined rate per ship-to = state_rate + county_rate + city_rate + special_rate.
• Tax per jurisdiction line = taxable_in_jurisdiction × that level's rate, rounded to the cent.
• Use tax = taxable_purchases_without_tax × applicable_rate (self-assessed).
• Total tax due = Σ jurisdiction tax + use tax.
• Net due = total_tax_due − vendor_discount (only if the state allows a timely-filing discount).
• Recompute all totals from the per-jurisdiction lines; flag any mismatch with the source.

Worked example (end-to-end)

Input — monthly sales summary (home-rule state)

Filer: Widgets LLC, State acct 12-345678-9, State: CO, Period: May 2026
Gross sales: 120,000
  Marketplace-facilitated (Amazon): 40,000
  Resale (certificate): 10,000
Taxable destination: Denver — state 2.90% + RTD/special 1.10% + Denver city 4.81% = 8.81%
Use tax: office supplies 1,000 untaxed @ 2.90% state

After classification + computation (intermediate)

taxable_sales = 120000 - 40000 - 10000 = 70000  (all destined to Denver)
state tax   70000 × 0.0290 = 2030.00
special tax 70000 × 0.0110 = 770.00
city tax    70000 × 0.0481 = 3367.00
use tax     1000 × 0.0290  = 29.00
total = 2030 + 770 + 3367 + 29 = 6196.00

Output — sales & use tax return dataset

{
  "filer": { "name": "Widgets LLC", "state_account": "12-345678-9" },
  "state": "CO",
  "period": { "start": "2026-05-01", "end": "2026-05-31" },
  "gross_sales": 120000.00,
  "deductions": {
    "marketplace_facilitator": 40000.00,
    "exempt_resale": 10000.00,
    "other": 0.00
  },
  "taxable_sales": 70000.00,
  "jurisdictions": [
    { "code": "CO-STATE", "level": "state", "rate": 0.0290, "taxable": 70000.00, "tax": 2030.00 },
    { "code": "CO-RTD",   "level": "special", "rate": 0.0110, "taxable": 70000.00, "tax": 770.00 },
    { "code": "DENVER",   "level": "city", "rate": 0.0481, "taxable": 70000.00, "tax": 3367.00 }
  ],
  "use_tax_due": 29.00,
  "total_tax_due": 6196.00,
  "vendor_discount": 0.00,
  "net_due": 6196.00
}

Normalisations shown: deductions subtracted (120000 − 40000 − 10000 = 70000); each jurisdiction tax recomputed from its own rate; use tax self-assessed 1000 × 2.90% = 29.00; total summed across lines 6196.00.

Validation checklist

• Nexus confirmed (physical or economic threshold) for the filing state; flagged if below
• Every sale classified: taxable, exempt/resale, or marketplace-facilitated
• Deductions documented (certificates / marketplace remittance) and subtracted from gross
• taxable_sales = gross_sales − Σ deductions
• Each jurisdiction line uses the correct current rate; local rates stacked by ship-to address
• Use tax self-assessed on untaxed taxable purchases
• total_tax_due = Σ jurisdiction tax + use tax; net_due applies discount only if allowed
• Rates and taxability confirmed against the state DOR / tax engine before filing

Last updated: 2026-06-13 — verify current state/local rates, economic-nexus thresholds, taxability rules, and the specific state return format before use.