VAT Sense Ruby SDK

The official Ruby library for the VAT Sense REST API. Validate VAT/EORI numbers, look up VAT/GST rates, calculate prices, convert currencies, and generate VAT-compliant invoices.

Installation

gem install vatsense

Or add to your Gemfile:

gem "vatsense"

Requires Ruby 3.2.0+.

Quick start

Create a client using your API key from the VAT Sense dashboard. The API uses HTTP Basic Auth with user as the username and your API key as the password.

require "vatsense"

client = Vatsense::Client.new(
  username: "user",
  password: "your_api_key",
)

You can also set the VAT_SENSE_USERNAME and VAT_SENSE_PASSWORD environment variables and the client will pick them up automatically.

Validate a VAT number

response = client.validate.check(vat_number: "GB288305674")

if response.data.valid
  puts response.data.company.company_name     # "BRITISH BROADCASTING CORPORATION"
  puts response.data.company.company_address
  puts response.data.company.country_code      # "GB"
end

VAT validation works for the UK, EU, Australia, Norway, Switzerland, South Africa, and Brazil.

Validate an EORI number

response = client.validate.check(eori_number: "GB123456789000")

if response.data.valid
  puts response.data.company.company_name
end

EORI validation is available for UK and EU numbers only.

Get a consultation number

If you need an official consultation number from VIES (EU) or HMRC (UK), provide your own VAT number as the requester:

response = client.validate.check(
  vat_number: "FR12345678901",
  requester_vat_number: "FR98765432101",
)

puts response.data.consultation_number

Note: GB requester numbers only work for GB validations, and EU requester numbers only work for EU validations. Cross-region requests are not supported.

Find the VAT rate for a country

rate = client.rates.find(country_code: "DE")

puts rate.data.country_name       # "Germany"
puts rate.data.tax_rate.rate      # 19.0
puts rate.data.tax_rate.class_    # "standard"

Find a rate for a specific product type

rate = client.rates.find(country_code: "DE", type: "ebooks")

puts rate.data.tax_rate.rate      # 7.0
puts rate.data.tax_rate.class_    # "reduced"

Find a rate by IP address

Useful for determining the correct rate based on your customer's location:

rate = client.rates.find(ip_address: "185.86.151.11")

puts rate.data.country_code       # "GB"
puts rate.data.tax_rate.rate      # 20.0

Calculate a VAT-inclusive price

result = client.rates.calculate_price(
  price: "100.00",
  tax_type: "excl",
  country_code: "FR",
)

puts result.data.vat_price.price_incl_vat  # Price including VAT
puts result.data.vat_price.price_excl_vat  # Price excluding VAT
puts result.data.vat_price.vat_rate        # VAT rate applied
puts result.data.vat_price.vat             # VAT amount

List all VAT rates

rates = client.rates.list

rates.data.each do |rate|
  puts "#{rate.country_code}: #{rate.country_name}"
end

# Filter to EU countries only
eu_rates = client.rates.list(eu: true)

Handling errors

When the API returns an error, the library raises a typed exception:

begin
  response = client.validate.check(vat_number: "GB288305674")
rescue Vatsense::Errors::APIConnectionError => e
  # Network issue, could not reach the API
  puts e.message
rescue Vatsense::Errors::RateLimitError => e
  # 429: Too many requests (300/min general limit, 3/sec for UK validation)
  puts "Rate limited, try again shortly"
rescue Vatsense::Errors::APIStatusError => e
  # Covers all other HTTP errors
  puts e.status
  puts e.message
end

A 412 error means the upstream validation service (VIES, HMRC, etc.) is temporarily unavailable. These requests do not count against your usage quota.

Status Code	Error Type
400	Vatsense::Errors::BadRequestError
401	Vatsense::Errors::AuthenticationError
404	Vatsense::Errors::NotFoundError
409	Vatsense::Errors::ConflictError
429	Vatsense::Errors::RateLimitError
>= 500	Vatsense::Errors::InternalServerError
N/A	Vatsense::Errors::APIConnectionError

Retries

Failed requests are automatically retried up to 2 times with exponential backoff. This includes connection errors, timeouts, 429, and 5xx responses.

# Disable retries
client = Vatsense::Client.new(
  username: "user",
  password: "your_api_key",
  max_retries: 0,
)

# Or configure per request
response = client.validate.check(
  vat_number: "GB288305674",
  request_options: { max_retries: 5 },
)

Available services

Service	Description
client.validate	Validate VAT and EORI numbers
client.rates	VAT/GST rate lookups, price calculations
client.countries	Country data and province lookups
client.currency	Exchange rates and currency conversion
client.invoice	Create and manage VAT-compliant invoices
client.usage	Check your API usage

Documentation

Full API documentation is available at vatsense.com/documentation.

Versioning

This package follows SemVer conventions. As the library is in initial development and has a major version of 0, APIs may change at any time.

Contributing

See the contributing documentation.