# Geoverio > REST APIs for US address, location and IP data: sales tax rates, address > autocomplete, and IP intelligence. One API key works across every API, every > endpoint is a single HTTPS request, and every response is JSON. Base facts an integration needs: - Auth: `Authorization: Bearer YOUR_API_KEY` on every request. Keys look like `gv_live_...`. - Keys are created at https://www.geoverio.com/dashboard/keys after signing up at https://www.geoverio.com/register (free tier, no card). - All endpoints are HTTPS GET unless stated otherwise; responses are JSON. - Rate limit state is returned on every response in `X-RateLimit-Limit`, `X-RateLimit-Remaining` and `X-RateLimit-Reset`. - Errors use standard HTTP status codes with a JSON body explaining the cause. ## APIs - [IP Lookup](https://www.geoverio.com/docs/ip-lookup.md): Geolocation, network owner, VPN/proxy/Tor detection and a risk score for any IP. Base URL `https://ip.geoverio.com`. Endpoints: GET /v1/ip/{ip}, GET /v1/ip/self, POST /v1/ip/batch. - [Sales Tax Finder](https://www.geoverio.com/docs/sales-tax.md): Accurate US sales tax rates by address or ZIP. Base URL `https://tax.geoverio.com`. Endpoint: GET /v1/tax. - [Address Autocomplete](https://www.geoverio.com/docs/address-autocomplete.md): Fast, typo-tolerant US address autocomplete. Base URL `https://autocomplete.geoverio.com`. Endpoint: GET /v1/autocomplete. - [Payroll](https://www.geoverio.com/docs/payroll.md): US payroll, gross to net, in one call.. Base URL `https://payroll.geoverio.com`. Endpoints: GET /v1/paycheck/quick, POST /v1/paycheck, POST /v1/paycheck/batch, POST /v1/paycheck/series, POST /v1/gross-up, POST /v1/employer-cost, POST /v1/statement/validate, GET /v1/jurisdictions, GET /v1/limits/{year}. ## Full reference - [Complete API reference, all APIs inlined](https://www.geoverio.com/llms-full.txt) - [Human-readable docs](https://www.geoverio.com/docs) - [Pricing and quotas](https://www.geoverio.com/pricing) ## About Geoverio Geoverio provides modular APIs for IP intelligence, US sales tax, address autocomplete, and payroll data to developers building modern products in the US market. The platform uses a single bearer token to access four distinct modules through one gateway while offering a permanent free tier and predictable per-request pricing. Official profiles: - https://www.geoverio.com ## Pages - [Home](https://www.geoverio.com/) — Geoverio provides modular APIs for IP intelligence, addresses, tax data, and US payroll. - [API catalog](https://www.geoverio.com/apis) — Browse every API on the Geoverio platform. - [Pricing](https://www.geoverio.com/pricing) — Geoverio prices its APIs by volume, not by feature: every plan reaches every API, and the tiers differ on monthly request quota and rate limit. - [Documentation home](https://www.geoverio.com/docs) — Beginner-friendly guides and a full reference for every Geoverio API: authentication, endpoints, response fields and working examples you can copy. - [Blog index](https://www.geoverio.com/blog) — Practical guides and honest deep dives from the Geoverio team, written for developers who work with IPs, addresses and the messy geography behind them. - [IP Lookup — product page](https://www.geoverio.com/apis/ip-lookup) — The Geoverio IP Lookup API returns geolocation, network owner, ASN, VPN/proxy/Tor detection and a risk score for any IPv4 or IPv6 address in one JSON response. - [Sales Tax Finder — product page](https://www.geoverio.com/apis/sales-tax) — The Geoverio Sales Tax API returns current US sales tax rates for an address or ZIP code, broken down by state, county, city and special district. - [Address Autocomplete — product page](https://www.geoverio.com/apis/address-autocomplete) — The Geoverio Address Autocomplete API suggests complete, valid US addresses as a user types, tolerating typos and partial input. - [Payroll — product page](https://www.geoverio.com/apis/payroll) — The Geoverio Payroll API turns one employee's pay inputs — earnings, W-4 data, jurisdictions, pre-tax deductions and year-to-date figures — into every federal, state and local tax… - [About Geoverio](https://www.geoverio.com/page/about) — Geoverio is a small team building one API platform for the data every product eventually needs: IP intelligence, address validation and autocomplete, US sales tax and payroll. - [Changelog](https://www.geoverio.com/page/changelog) — The Geoverio changelog lists every platform and API change, newest first. - [Data Processing Addendum](https://www.geoverio.com/page/dpa) — Geoverio's data processing addendum covers the case where your API requests contain personal data belonging to your own users — you act as the controller and Geoverio as the proce… - [Privacy Policy](https://www.geoverio.com/page/privacy) — Geoverio's privacy policy explains what the platform collects, why it is collected, how long it is kept, and which processors handle it. - [Security](https://www.geoverio.com/page/security) — This page describes how Geoverio is built and operated: encryption in transit, API key handling, access control, backups and incident response. - [Talk to sales](https://www.geoverio.com/page/contact-sales) — Geoverio's self-serve plans go up to 5,000,000 requests a month. - [Terms of Service](https://www.geoverio.com/page/terms) — Geoverio's terms of service govern the APIs, dashboard and website: what an account may do, rate limits and fair use, billing and cancellation, uptime expectations and liability. ## Articles - [Calculate US Payroll with One API Call: Geoverio Payroll Module](https://www.geoverio.com/blog/calculate-us-payroll-one-api-call) — Learn how to calculate US payroll in a single API call using Geoverio’s Payroll module. - [How to Use the Geoverio IP Risk Score to Flag High‑Risk Orders](https://www.geoverio.com/blog/ip-risk-score-flag-high-risk-orders) — Learn step‑by‑step how to apply Geoverio’s IP risk score in your checkout flow. - [Combining IP Lookup & Sales Tax Finder for Real‑Time Checkout Compliance](https://www.geoverio.com/blog/combine-ip-lookup-sales-tax-finder) — Learn how to pair Geoverio’s IP Lookup and Sales Tax Finder APIs to enforce e‑commerce compliance instantly at checkout, with one API key and a clear pricing model. - [vpn detection api: real‑time IP Lookup for fraud prevention](https://www.geoverio.com/blog/vpn-detection-api-real-time-ip-lookup) — Learn how to integrate Geoverio’s IP Lookup API to spot VPN, proxy, and Tor usage instantly. - [Validate US Addresses Before Sales Tax Requests](https://www.geoverio.com/blog/validate-us-addresses-before-sales-tax-requests) — Use our address validation API to clean inputs before sending sales tax calls. - [How multi-state payroll APIs automate tax compliance](https://www.geoverio.com/blog/how-multi-state-payroll-apis-automate-tax-compliance) — Stop updating spreadsheets. - [Five places payroll math goes quietly wrong](https://www.geoverio.com/blog/five-places-payroll-math-goes-quietly-wrong) — A wrong paycheck looks exactly like a right one until somebody's W-2 is wrong in February. - [What an IP geolocation API can and can't tell you](https://www.geoverio.com/blog/what-an-ip-geolocation-api-can-and-cant-tell-you) — IP location data comes from routing records, not GPS. ## Glossary - **address normalization** — A process that standardizes inconsistent street inputs into a single, machine-readable format used by postal services for delivery. - **ASN** — An Autonomous System Number uniquely identifies a network block on the internet and reveals its owner or provider. - **effective tax rate** — The actual percentage of taxable income paid after accounting for all credits and deductions specific to a business location. - **federal withholding amount** — The specific tax dollars deducted from an employee's paycheck to cover their estimated annual federal income tax liability. - **ISP** — The Internet Service Provider associated with an IP address shows which company owns the network segment you are connecting to. - **locality rules** — The varying tax thresholds or physical footprints required in specific states before a business must register for local tax collection. - **net pay** — The final amount deposited into an employee's bank account after all required deductions like taxes and insurance are removed. - **network owner lookup** — The process of identifying the organization or ISP associated with an IP address and displaying their contact details for abuse reporting. - **postal carrier delivery point** — The final physical location where a mail package stops on its route, often derived from zip plus four codes but confirmed by carrier routes. - **proxy IP** — An address that forwards requests from a user without revealing their true origin, commonly used for anonymity but detectable via header analysis. - **risk score** — A numeric value that rates how likely an IP is used for fraud based on historical abuse data, blacklists, and geographic anomalies. - **sales nexus** — The specific physical or digital connection between a company and a state that legally requires you to collect and remit sales tax there. - **street center point** — A precise latitude and longitude coordinate calculated from the midpoint of a physical street address block for accurate mapping. - **Tor exit node** — A server on the Tor network where encrypted traffic emerges from the dark web before heading to its final destination, often flagged by our risk models. - **validation confidence score** — A metric between zero and one that indicates how certain our system is about the accuracy of an entered street or ZIP code. - **VPN detection** — This check identifies if an IP address hides behind a Virtual Private Network by analyzing header patterns and network behavior. - **Gross-up** — Working backwards from the amount an employee should receive to the gross that produces it after tax. Because withholding is not a flat percentage, an accurate gross-up has to run the full calculation rather than divide by an assumed rate — otherwise it drifts whenever the employee is near a wage-base cap or a bracket edge. - **Wage base** — The annual earnings ceiling above which a given payroll tax stops applying. Social Security has one; Medicare does not. Because the ceiling is annual, whether a particular paycheck crosses it depends on every paycheck before it in the year, which is why year-to-date figures have to be carried from one pay period into the next. - **Additional Medicare Tax** — An extra 0.9% withheld from an employee's wages once their year-to-date earnings pass a statutory threshold. The employer does not match it. Like the Social Security wage base it is an annual boundary, so the paycheck it starts on depends on the pay history before it. - **Pay statement** — The itemised record of a single paycheck given to the employee. No federal statute prescribes its contents, but most states do, and the required items differ by state — which means a stub can be arithmetically correct and still not lawful where the employee works. ## Reading pages as text Append `?format=md` to any page URL on this site to get the same content as Markdown, without navigation or scripts. Example: https://www.geoverio.com/pricing?format=md ## Questions and answers ### Home **Is there a free tier for Geoverio APIs?** Yes, the service offers a permanent free tier requiring no credit card. One account gets 1,000 monthly requests with community support. **How do I authenticate to the API?** You use a single bearer token that works for all four published API modules. The same key covers every endpoint without needing separate credentials. **What happens when my free quota is exceeded?** If you stop at the zero balance on the pay-as-you-go plan, no surprise bills occur. Other plans allow higher limits but charge a monthly fee. ### API catalog **What is Geoverio?** Geoverio provides modular APIs that give access to IP Lookup, Sales Tax Finder, Address Autocomplete, and Payroll. Developers use one bearer token to authenticate with all modules. **Is there a free option?** The platform includes a free tier for new users looking to test the services without immediate costs. **Do all Geoverio APIs use the same API key?** Yes. One bearer token works across every module — IP Lookup, Sales Tax, Address Autocomplete and Payroll — and every plan reaches every API. There is nothing separate to enable per module. ### Address Autocomplete — product page **What does the Address Autocomplete API do?** Fast, typo-tolerant US address autocomplete. **How do I authenticate with the Address Autocomplete API?** Send your key as a bearer token: `Authorization: Bearer `. One key works across every Geoverio API your plan includes. **Is there a free tier?** Yes. Every plan reaches every API; the free tier differs on monthly volume and rate limit, not on which endpoints you may call. ### IP Lookup — product page **What does the IP Lookup API do?** Geolocation, network owner, VPN/proxy/Tor detection and a risk score for any IP. **How do I authenticate with the IP Lookup API?** Send your key as a bearer token: `Authorization: Bearer `. One key works across every Geoverio API your plan includes. **Is there a free tier?** Yes. Every plan reaches every API; the free tier differs on monthly volume and rate limit, not on which endpoints you may call. ### Payroll API — product page **What does the Geoverio Payroll API do?** It calculates US payroll from gross to net. You send one employee's earnings, W-4 data, work jurisdictions, pre-tax deductions and year-to-date figures; it returns every federal, state and local tax, every deduction, net pay, updated year-to-date, a render-ready pay statement, and the items that employee's jurisdiction requires on a wage statement. **What is the difference between the batch and series endpoints?** Batch is many employees in one pay period, and the employees are independent, so they run side by side — up to 200 in a call. Series is one employee across many pay periods, and the periods are not independent: Social Security stops at the annual wage base and Additional Medicare starts above a threshold, so each period has to feed year-to-date into the next. Running this Friday's payroll for forty people is a batch call. Reconstructing a year of pay stubs for one person is a series call. **Does the Geoverio Payroll API store employee data?** No. Year-to-date is an input and an output, request bodies are never logged, and no employer, employee or paycheck record is kept. The API can sit inside your product without becoming a second system of record you have to secure. **What happens if a state is not supported?** The call returns a structured 422 that names exactly what is missing for that jurisdiction. It never returns a zero. A silent zero is a wrong paycheck nobody notices until the filing, so the engine refuses to produce one. In a batch run, that employee comes back in an errors list with the reason and the rest of the run still calculates. GET /v1/jurisdictions reports the status of every jurisdiction before you rely on one. **Can it calculate a gross-up?** Yes. POST /v1/gross-up answers "give them $1,000 in hand — what does that cost in gross?" by running the full engine rather than dividing by an assumed rate, so wage-base caps and bracket edges are respected instead of averaged away. **Can it tell me whether a pay stub is legal?** POST /v1/statement/validate takes a pay statement and returns what the employee's jurisdiction requires on a wage statement, which of those items you already supply, and which are still missing. Every paycheck response also carries the required items alongside the numbers. **Does it file or remit taxes?** No. It calculates and returns numbers; it transmits nothing to any tax authority and holds no money. Filing and remittance stay with you or your provider. ### Sales Tax Finder — product page **What does the Sales Tax Finder API do?** Accurate US sales tax rates by address or ZIP. **How do I authenticate with the Sales Tax Finder API?** Send your key as a bearer token: `Authorization: Bearer `. One key works across every Geoverio API your plan includes. **Is there a free tier?** Yes. Every plan reaches every API; the free tier differs on monthly volume and rate limit, not on which endpoints you may call. ### Blog index **What data does Geoverio provide?** The site offers guides on IP, address and tax data for developers working with geolocation and sales tax rates. **How accurate is the payroll API?** It handles US gross-to-net calculations instantly for any employee address in a single call. **Where can I find more information?** You can read practical guides and honest deep dives written by the Geoverio team on the blog. ### Five places payroll math goes quietly wrong **Why do payroll calculators return wrong paychecks?** Because a wrong paycheck looks exactly like a right one. The five common causes are: calculating a pay period without the year-to-date history that decides where the Social Security wage base and the Additional Medicare threshold fall; returning a zero for a jurisdiction the engine does not actually support; selecting tax tables by calendar year when the jurisdiction changed them mid-year; treating every pre-tax deduction the same when states disagree about them; and producing correct numbers on a pay statement that is missing items the state legally requires. **Why does year-to-date matter for a single paycheck?** Two of the largest federal figures are annual rather than per-paycheck. Social Security stops once year-to-date wages reach the wage base, and Additional Medicare starts once they pass a threshold. Both boundaries are crossed in the middle of a pay period, so whether a given paycheck is correct depends on every paycheck before it in the year. **Is a pre-tax deduction pre-tax in every state?** No. Pennsylvania taxes 401(k), 403(b), 457(b) and SIMPLE IRA contributions at the state level even though they reduce federal taxable wages, while Section 125 contributions are excluded from both. California excludes Section 125 and 401(k) but taxes HSA contributions that are excluded federally. An engine with a single "pre-tax" flag per deduction gets both wrong, in the direction that under-withholds. **Can a pay stub be correct and still be illegal?** Yes. No federal statute prescribes what a pay statement must contain, but most states do and they differ. A stub can be arithmetically perfect and still omit an item the employee's state requires on it, which is a compliance failure rather than a math error. ### How multi-state payroll APIs automate tax compliance **How do I update tax rates without manual effort?** The system updates rates automatically based on official filings when you make a request with an address or ZIP code. **What happens if a user moves to a new state like Texas?** The next API request reflects the zero income tax environment in that state immediately without needing database updates on your end. **Is this useful for distributed work teams?** Yes, it keeps payroll simple regardless of where users live by calculating take-home pay using federal taxes and specific state deductions. ### What an IP geolocation API can and can't tell you **Can I use this for US sales tax?** Yes, the platform includes a Sales Tax Finder module that provides accurate US sales tax rates by address or ZIP. **Does the API detect VPNs?** The IP Lookup module detects VPN exits, open proxies, and Tor relays to help identify anonymized traffic. ### Documentation home **Do I need to install software to use Geoverio?** No prior experience is required. You create a free account by picking an email and password, then grab your API key from the dashboard before making your first call. **Where should I store my API key?** Keep the key in your server environment variables. Never paste it in public chats, screenshots, or code you push to GitHub to keep it secret. **Can AI assistants parse error responses correctly?** Yes. An expired key returns a 401 status with a valid JSON envelope. You must check the status before parsing the body to handle errors properly. ### Address Autocomplete — docs **What does the Address Autocomplete API do?** Fast, typo-tolerant US address autocomplete. **How do I authenticate with the Address Autocomplete API?** Send your key as a bearer token: `Authorization: Bearer `. One key works across every Geoverio API your plan includes. **Is there a free tier?** Yes. Every plan reaches every API; the free tier differs on monthly volume and rate limit, not on which endpoints you may call. ### IP Lookup — docs **What does the IP Lookup API do?** Geolocation, network owner, VPN/proxy/Tor detection and a risk score for any IP. **How do I authenticate with the IP Lookup API?** Send your key as a bearer token: `Authorization: Bearer `. One key works across every Geoverio API your plan includes. **Is there a free tier?** Yes. Every plan reaches every API; the free tier differs on monthly volume and rate limit, not on which endpoints you may call. ### Payroll API — reference **How do I authenticate with the Geoverio Payroll API?** Send your key as a bearer token: Authorization: Bearer . There is no other auth scheme — no query-string keys, no signing, no OAuth — and the same key works across every Geoverio API your plan includes. **How do I check whether a state is supported before I build on it?** Call GET /v1/jurisdictions. It returns every jurisdiction with its status — supported, partial or unsupported — the withholding method used, the official source behind it, and the local jurisdictions covered. **Where do the tax rates and limits come from?** GET /v1/limits/{year} returns the year's Social Security wage base, Medicare and Additional Medicare thresholds, FUTA rates and credit reductions, supplemental rates, and the 401(k), HSA, FSA and commuter limits. Behind them, every figure in the engine has a manifest entry recording its source URL, retrieval date and verification method. **Can I calculate employer cost as well as employee withholding?** Yes. POST /v1/employer-cost returns the employer side: Social Security and Medicare matches, FUTA including any state credit reduction, and SUTA from a rate you supply — state unemployment rates are assigned per employer and are not public data. ### Sales Tax Finder — docs **What does the Sales Tax Finder API do?** Accurate US sales tax rates by address or ZIP. **How do I authenticate with the Sales Tax Finder API?** Send your key as a bearer token: `Authorization: Bearer `. One key works across every Geoverio API your plan includes. **Is there a free tier?** Yes. Every plan reaches every API; the free tier differs on monthly volume and rate limit, not on which endpoints you may call. ### About Geoverio **Do I need a credit card to start?** No, the free tier requires no credit card and provides enough volume to build something real. **How do I handle integration changes?** You add another module without changing your integration, requiring no new credential or client. **Which certifications does Geoverio currently hold?** The Security page explicitly tells you which certifications are not yet held so you know exactly what you are buying. ### Changelog **Is there a free tier for Geoverio APIs?** Geoverio offers an optional free tier alongside predictable pricing and an available Enterprise tier. **How do I get started with the platform?** Developers can access all modules using one API key and read documentation that includes copyable code samples. **What security features does Geoverio provide?** Account security includes two-factor authentication by authenticator app or emailed one-time code, along with hashed recovery codes. ### Talk to sales **Does Geoverio require a credit card for the free tier?** No, the free tier needs no credit card and lets you make authenticated calls in minutes. **How quickly do sales teams reply to inquiries?** The team replies within one business day after receiving details on APIs and volume. ### Data Processing Addendum **What is the role of Geoverio in data processing?** Geoverio acts as the processor while you serve as the controller when sending personal data. **When must Geoverio notify about a breach?** They will notify within 72 hours of becoming aware of a personal data breach. **Do I need to sign anything to use these APIs?** Accepting these terms is required, but a signature is only needed if your procurement process demands one. **Are special category data supported?** No special category data should be sent to these endpoints as none are supported. ### Privacy Policy **Does Geoverio sell personal data?** No. We do not sell personal data, nor do we use API request content to build advertising or profiling products. **How long are sign-in attempt records kept?** We record the IP address of sign-in attempts for two days before automatically deleting them. **Who is responsible for API request content?** When you send us API requests, you act as the controller for that content while we serve as the processor. ### Security **How are passwords secured at Geoverio?** Passwords are hashed with Argon2id and a server-side pepper, meaning a database copy alone does not yield credentials. Two-factor authentication is available via authenticator app or emailed one-time code. **What happens if I find a security vulnerability?** Report it to the provided email address with enough detail to reproduce the issue. We acknowledge within two business days and will keep you updated until it is resolved. **Is card data processed on Geoverio servers?** No, card data never touches our servers as payments are handled entirely by Stripe, which is PCI DSS Level 1 certified. This keeps the API out of scope for PCI DSS. ### Terms of Service **How do I secure my API keys?** You must keep keys on your server in an environment variable, never in client-side code or a public repository. If a key is exposed, revoke it in your dashboard immediately. **What happens if I exceed my minute limit?** Requests beyond your per-minute limit receive a 429 response and are not billed. Rejected authentication and validation errors also do not consume quota. **Does Geoverio refund partial periods?** The service generally does not refund partial periods after cancellation, though you can write to them if the service materially failed to work as described. ### Pricing **How much does Geoverio cost?** See the plan table on this page for the current monthly prices. Every plan includes every API. **Is there a free plan?** Yes — a free tier with a monthly request quota, available once per account.