Create Calculations

Get tax information for a given product and address or IP

POST /tax/calculations

cURL

2024-09-01

curl --request POST \
  --url https://api.numeralhq.com/tax/calculations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-API-Version: <x-api-version>' \
  --data '
{
  "customer": {
    "address": {
      "address_line_1": "4 Privet Drive",
      "address_city": "Little Whining",
      "address_province": "CA",
      "address_postal_code": "90210",
      "address_country": "US",
      "address_type": "shipping"
    }
  },
  "order_details": {
    "customer_currency_code": "USD",
    "tax_included_in_amount": false,
    "line_items": [
      {
        "reference_product_id": "wand_elder_12",
        "amount": 10000,
        "quantity": 1
      }
    ]
  }
}
'

200

2024-09-01

{
  "id": "calc_1726683504829b84b2ad6-a4c9-4e0e-986f-7bb3d1fb17c9",
  "object": "tax.calculation",
  "customer_currency_code": "USD",
  "line_items": [
    {
      "product": {
        "reference_product_name": "Elder Wand",
        "reference_product_id": "wand_elder_12",
        "product_tax_code": "GENERAL_MERCHANDISE"
      },
      "tax_jurisdictions": [
        {
          "tax_rate": 0.1,
          "rate_type": "SALES TAX",
          "jurisdiction_name": "California",
          "fee_amount": 0
        }
      ],
      "quantity": 1,
      "tax_amount": 1000,
      "amount_excluding_tax": 10000,
      "amount_including_tax": 11000
    }
  ],
  "tax_included_in_amount": false,
  "total_tax_amount": 1000,
  "total_amount_excluding_tax": 10000,
  "total_amount_including_tax": 11000,
  "expires_at": 1726683511,
  "testmode": true,
  "address_resolution_status": "EXACT",
  "address_used": {
    "address_line_1": "4 Privet Drive",
    "address_city": "Little Whinging",
    "address_province": "CA",
    "address_postal_code": "90210",
    "address_country": "US"
  }
}

Get tax information for a given product and address

Caution about simply summing tax_rate values. Each tax_rate in tax_jurisdictions is the statutory rate for that jurisdiction, and in some jurisdictions a rate applies to only part of the line item amount. Tennessee’s single article rules are the common example: local rates apply only to the first $1,600 of an item, and the 2.75% state single article rate applies only to the portion between $1,600 and $3,200. For a $10,000 item the returned rates sum to 12.25%, but the tax due is $788, an effective rate of 7.88%.

Always charge the returned tax_amount (or total_tax_amount). If you need an effective rate, compute tax_amount / amount_excluding_tax from the response rather than adding up tax_rate values. Jurisdictions whose rate applies to only part of the amount carry a note value other than RATE_FRAC, such as PROGRESSIVE_RATE.

cURL Header Example

Include all request headers explicitly:

curl --request POST \
  --url https://api.numeralhq.com/tax/calculations \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --header 'X-API-Version: 2024-09-01' \
  --data '{ ... }'

Authorizations

Authorization · string · header · required

Bearer authentication header of the form Bearer <token>, where <token> is your auth token.

Headers

X-API-Version · enum<string> · required

API version to use.

Available options: 2026-03-01, 2026-01-01, 2025-05-12, 2024-09-01

Body

application/json

API Version 2026-03-01

API Version 2026-01-01

API Version 2025-05-12

API Version 2024-09-01

customer · object · required

Customer details. At least one of address or ip must be provided.

Show child attributes

origin_address · object · required

Required from API version 2025-05-12+. The address that a product is shipped from.

Show child attributes

order_details · object · required

Show child attributes

metadata · object

You can store arbitrary keys and values in the metadata. Any valid JSON object whose values are less than 255 characters long is accepted.

Show child attributes

default_customer_type · enum<string>

Optional fallback customer type used when customer.id is provided but no matching customer exists in Numeral. Lets integration partners always pass a customer ID without first ensuring the customer has been created. When the lookup misses, this value drives tax-exemption logic and business tax-ID validation as if it were customer.type. If a matching customer is found, the stored customer.type takes precedence. Available in API version 2026-03-01 and later.

Available options: CONSUMER, BUSINESS

Example:

"CONSUMER"

Response

200

application/json

Calculate response

id · string

The ID of the calculation. You will use this to create a transaction.

Example:

"calc_123456789"

object · string

The type of object: tax.calculation.

Example:

"tax.calculation"

customer_currency_code · string

The ISO-4217 currency code of the transaction.

Example:

"USD"

customer · object

Customer information returned in the response.

Show child attributes

automatic_tax · enum<string>

The automatic tax setting for this calculation.

Available options: auto, disabled

Example:

"auto"

line_items · object[]

Show child attributes

tax_included_in_amount · boolean

Example:

false

total_tax_amount · number

Total tax to charge on this calculation.

Example:

14

total_amount_excluding_tax · number

Total sale charge, excluding tax.

Example:

200

total_amount_including_tax · number

Total sale charge plus tax. What you should charge your customer.

Example:

214

expires_at · number

Epoch datetime representing the date and time the tax rates are valid until.

Example:

1714787673

testmode · boolean

True if using a production API key. False if using a test API key.

Example:

"false"

address_resolution_status · enum<string>

Status of address resolution for the customer address. EXACT: exact address match found, POSTAL_FALLBACK_1: used postal code fallback, POSTAL_ONLY: only postal code was used for tax calculation.

Available options: EXACT, POSTAL_FALLBACK_1, POSTAL_ONLY

Example:

"EXACT"

address_used · object

The actual address used for tax calculation after resolution.

Show child attributes

metadata · object

You can store arbitrary keys and values in the metadata. Any valid JSON object whose values are less than 255 characters long is accepted.

Show child attributes

location_source · enum<string>

Which input was used for tax determination.

Available options: address, ip

Example:

"address"

resolution_precision · enum<string>

The precision level of the resolved location.

Available options: STREET, POSTAL_PLUS, POSTAL, PROVINCE, COUNTRY, APPROXIMATED

Example:

"POSTAL"