Overview

The API combines VAT-number validation, tax rates, currency conversion, country data and VAT-compliant invoicing. Every plan includes the full API, so moving to a higher tier increases request capacity rather than unlocking a different feature set. That makes the choice primarily about expected volume.

VAT checks query live records in the UK, EU, Australia, Norway, Switzerland, South Africa and Brazil. The API also provides EU VAT rates and VAT and GST rates from other countries, with VAT calculation across 179 jurisdictions. Currency conversions to GBP and EUR use HMRC and European Central Bank rates. A validation can return an official government consultation number when the request includes the caller’s own VAT number, giving the result an audit reference.

Key features

Tax and currency data: Validation, rates, calculation and conversion sit behind one REST API. That is a practical fit for a server-side workflow that needs multiple tax inputs without stitching together separate services.
Developer tooling: Official libraries cover Python, Node.js, PHP, Go, Ruby, C#/.NET and Java, and the documentation links to Postman collections. Teams using these languages have a direct integration path; other stacks can use the REST API.
Authentication and transport: Requests require HTTPS and HTTP Basic Auth. The maker says the API uses 256-bit SSL and does not support client-side CORS requests because browser code could expose account keys. This is sensible for credential security, but means a browser app needs a server-side component to make calls.
Request limits: General limits are 300 requests per minute, with UK VAT validation capped at 3 requests per second. Workloads with validation bursts should account for the tighter UK-specific ceiling as well as their monthly plan quota.

Pricing

VAT Sense is freemium. Its plan details show monthly and annual billing in euros; prices are exclusive of VAT, and payment can be made in GBP, USD or EUR. The maker’s pricing note says paid access starts at $6.99/mo, while the plan amounts below are the listed euro billing terms.

Free: €0.00/mo for 100 requests per month. It is a small allowance for evaluation or very low-volume use, not a generous production quota.
Starter: €5.99/mo or €57.50/yr for 500 requests per month. It suits a modest workload that needs more than the free cap; the quota remains tight for frequent checks.
Basic: €11.99/mo or €115.10/yr for 2,000 requests per month. This is a better fit for regular but bounded usage.
Standard: €34.99/mo or €335.90/yr for 10,000 requests per month. It raises capacity substantially while retaining the same API feature set.
Plus: €69.99/mo or €671.90/yr for 25,000 requests per month. Consider it for higher-throughput integrations that can forecast demand.
Premium: €119.99/mo or €1,151.90/yr for 50,000 requests per month. It provides the largest stated quota, though the per-minute and UK validation limits still matter for bursty traffic.

The six plans differ by request allowance rather than API access. Choose a tier against expected monthly volume and the applicable per-minute limits; the lower tiers trade capacity for lower recurring cost.

Platforms

VAT Sense is offered as an API. It is a building block for software integrations rather than a standalone desktop or mobile app. The London-based maker provides a support page for contacting the company.

Who it's for

VAT Sense is a good fit for developers and teams integrating tax validation, rates, conversion or invoicing into a server-side product, particularly when they can use one of its official libraries. It is less suitable for browser-only implementations that cannot route requests through a backend, or for workloads whose request peaks exceed its rate limits.

Pros and cons

Pro: One API covers validation, VAT and GST rates, currency conversion, country data and VAT-compliant invoicing, reducing the need to assemble these functions separately.
Pro: Live-record checks span seven named markets, and the optional consultation number gives a validation an official audit reference.
Pro: Libraries for seven languages and Postman collections make it easier to work from an existing developer stack.
Con: No client-side CORS calls are supported, so browser apps need a server component to protect credentials.
Con: The free plan allows just 100 requests monthly, and UK validation has a 3-per-second limit even when the general limit is higher.

Alternatives

VAT Software is the broader category directory for comparing VAT tools.

LOVAT is worth considering when a free trial, Android or iOS access, or a data-import integration is more relevant than an API-only setup.
VAT Direct may suit UK businesses seeking free bridging for VAT and Income Tax Self Assessment, with digital records for businesses below the VAT threshold up to 500 transactions per period.
VATlayer is another API option; its free plan allows 100 monthly requests for non-commercial use with limited functionality.
Vatstack may be a better fit for developers who need unlimited quotes and dummy validations on its free Developer plan rather than live VAT Sense validation.
Kintsugi is another API option, with a free plan covering global physical and economic nexus monitoring, exposure and historical liability auditing, and risk assessment.
hellotax is an alternative to consider for seller-focused plans that specify transaction and integration allowances.
Sphere is a paid API and web option whose Starter plan bundles monitoring, registration, filing and remittance, local rails and integrations for fewer than 10 regions.
Stripe Tax is another paid API option, with no-code and API integration plans.

Verdict

Choose VAT Sense if your team needs live VAT checks plus rates, conversion and related tax functions through one server-side API, and can size its request volume to the plan quotas. Its main advantage is breadth with familiar developer libraries; look elsewhere if browser-only access is essential or your traffic cannot fit the monthly and rate limits.

	Kleos	VAT Sense
Free plan	No	Yes
Free trial	No	No
Paid from	—	Free
Open source	No	No
Platforms	Android, iOS	api
Free plan	—	Yes
Paid from	—	6.99 /mo
VAT calculation	—	Yes
VAT jurisdictions	—	179 countries
E-invoicing support	—	basic

Kleos vs VAT Sense

Kleos

VAT Sense