Frequently Asked Questions

DQVerify is a US data validation platform that verifies postal addresses, email addresses, and phone numbers from one account — one API key, a dedicated endpoint for each channel, and credit packs bought per check type.

Unlike traditional validation vendors that require procurement cycles, SFTP file transfers, and enterprise contracts, DQVerify is fully self-serve: sign up with a business email, receive 1,000 free credits, and start immediately — no credit card, no sales call. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026.

• Address validation — standardization with USPS CASS Certified software, ZIP+4 correction and USPS DPV deliverability confirmation for US addresses, and licensed postal data for 240+ countries and territories
• Email validation — live SMTP handshake, MX record check, and disposable domain detection
• Phone validation — real-time carrier lookup and line-type identification (mobile / landline)

API response time is under 150ms at the 95th percentile, with 99.99% average uptime.

DQVerify validates three types of contact data through a single integration. Each module is billed separately at one credit per call.

• Address — standardizes the address, corrects and returns the ZIP+4, confirms deliverability with USPS DPV, and returns a result code: valid as entered, corrected, or missing something such as a street number or unit
• Email — MX record lookup, live SMTP handshake, disposable domain and spam trap check; returns a Low / Medium / High risk score
• Phone — identifies carrier, classifies line type (mobile or landline), confirms active/ported status

Each validation is its own API call. Validating all three for one record costs 3 credits (one per module), each drawn from the pack for its check type, with the same API key.

Yes. US addresses are processed with USPS CASS (Coding Accuracy Support System) Certified software supplied by a USPS licensee. The certification belongs to that software, not to DQVerify itself.

Each US address check, in real time or in a batch file, corrects and returns the ZIP+4, confirms deliverability with USPS DPV (Delivery Point Validation), and returns the address in standardized form with a result code that says whether it is valid as entered, was corrected, or is missing something such as a street number or unit.

Mailing at USPS automation prices takes more than standardized addresses: the USPS also requires a CASS Summary Report (PS Form 3553) and Move Update processing such as NCOALink. Talk to the team before relying on DQVerify output for postal discounts.

Beyond the core address, email, and phone modules, DQVerify offers supplementary data services available on Verify and Enterprise plans:

• Email activity scoring — identifies whether an address has been recently active, reducing false positives beyond deliverability
• B2B enrichment — appends company, industry, and firmographic data to validated business contacts
• Mooved detection — flags contacts who have recently changed address, enabling proactive record updates
• ID Check — validates identity against partner databases for KYC and onboarding workflows
• Geolocation — appends latitude and longitude to validated addresses

Contact the team for specifics on any module.

DQVerify Standalone is the web-based platform version of DQVerify — no API integration, no code, no SFTP required. It supports two modes:

• Real-time validation — enter a single address, email, or phone record and get an instant validated result in the browser
• Batch validation — upload a CSV or spreadsheet, point your columns to the correct fields using a flexible mapping interface (no rigid column format required), and download an enriched output file

DQVerify connects directly to your data wherever it lives — cloud platforms like AWS or Azure, data warehouses like Snowflake, or a simple CSV upload. No data migration required. Available on Verify and Enterprise plans.

Yes. Address, email, and phone each have their own endpoint (/external/validate/address, /email, and /phone), so each validation is a separate API call — but all three use the same API key, and each draws one credit from the pack for its check type. Calls can run in parallel and typically return in under 150ms.

Each module is billed separately (1 credit per address, 1 credit per email, 1 credit per phone), but you only need one API key — replacing the typical stack of:

• Address validation — Smarty or Melissa (separate key + billing)
• Email validation — ZeroBounce or NeverBounce (separate key + billing)
• Phone validation — Twilio Lookup or Numverify (separate key + billing)

DQVerify email validation runs a multi-step sequence:

• MX record check — confirms the domain is configured to receive email
• Live SMTP handshake — tests whether the specific address is accepted by the receiving mail server without delivering a message
• Reputation check — cross-references disposable providers (e.g. Mailinator), role-based prefixes (admin@, noreply@), and known spam trap addresses

The result is a risk score (Low / Medium / High) plus structured error codes for routing logic:

• 00 — valid
• 01 — valid but username unconfirmed
• 02 — address not found in domain
• 03 — inbox full
• 04 — empty
• 91 — syntax error
• 92 — non-existent domain
• 93 — blacklisted domain
• 94 — reserved or role-based name
• 95 — disposable email
• 96 — IP blocked
• 99 — domain not responding

A validated address response includes:

• The standardized address, split into fields: street number, street type, street name, unit or other secondary information, city, postal code, and country
• For US addresses, the ZIP+4 (corrected when the input ZIP is wrong or incomplete) and USPS DPV deliverability confirmation
• A result code and validation status — valid as entered, valid and corrected, or not valid
• A simplified OK / KO flag for routing
• Latitude and longitude, when available

For inputs that cannot be validated, the result code says why, so your application can route the record. The response schema is consistent across all outcomes, and the full list of codes is in the Help Center under API response codes.

Yes. DQVerify supports address validation across 240+ countries and territories using the same API key and address endpoint.

• UK — Royal Mail PAF standard
• Europe — national postal authority databases
• Asia-Pacific and Latin America — regional postal standards

US addresses are processed with USPS CASS Certified software. International addresses are validated against licensed postal authority datasets — CASS is a US-only standard and does not apply to international lookups.

Smarty focuses on address and location data. DQVerify validates addresses, emails, and phone numbers through a single integration, with one API key.

For US addresses, both use USPS CASS Certified software (DQVerify through a USPS licensee), both return the ZIP+4 and USPS DPV confirmation, and both cover international addresses. DQVerify's address endpoint takes its own input format, so moving from Smarty means updating the request body, not only the base URL. The developer docs show the format.

From sign-up to first validated record in under five minutes:

• 1. Create a free account with a business email or Google SSO — no credit card required. You receive 1,000 free credits immediately. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026.
• 2. Copy your API key from the dashboard.
• 3. Send a POST request to the address, email, or phone endpoint — one call per validation. Working code snippets for curl, Python, Node.js, and PHP are provided in the dashboard.

The API uses standard JSON bodies, standard HTTP status codes, and the same authentication across all three validation types.

Yes — DQVerify connects directly to your data wherever it lives, with no code or SFTP setup required:

• CSV or spreadsheet upload — map your columns using a drag-and-drop interface and download an enriched output file
• Cloud connectors — connect directly to data stored on AWS, Azure, Google Cloud, or warehouses like Snowflake
• Files under 50,000 rows typically complete in under ten minutes
• Larger files process asynchronously and deliver results via webhook or dashboard link

US addresses in batch files are processed with USPS CASS Certified software. Available on Verify and Enterprise plans.

DQVerify offers three tiers — no monthly subscription on any plan. Every tier uses the same API, the same response format, and the same validation engine. The only difference is volume and support level.

• Validate (free) — 1,000 credits at signup, no credit card required. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026. Use all three validation types (address, email, phone) to evaluate DQVerify on your own data before committing.
• Verify — one-time credit purchase starting at $275 for 20,000 credits, with volume tiers up to 500,000. Pricing varies by module because each draws on different licensed data sources (USPS postal data, SMTP infrastructure, carrier networks). Credits are valid for 1 year from purchase — no monthly renewal, no auto-charge.
• Enterprise — for organizations needing CRM connectors (Salesforce, Shopify), volumes above 500,000, or compliance features like dedicated SLAs and security documentation (DQE Software SAS is ISO 27001 certified). Custom pricing based on volume and module mix — contact the team for a quote.

Each module draws on a different licensed data source with its own cost structure, and DQVerify passes that difference through transparently rather than hiding it in a blended rate:

• Address — US addresses are processed with USPS CASS Certified software supplied by a USPS licensee, using licensed USPS data for ZIP+4 correction and DPV deliverability confirmation. International addresses are checked against licensed postal authority data.
• Email — live SMTP infrastructure and continuously updated disposable-domain and spam-trap databases. Every validation opens a real-time connection to the recipient's mail server, which carries operational cost per lookup.
• Phone — real-time carrier network lookups for line-type identification (mobile, landline, VoIP). Carrier data is sourced from licensed telecom databases that charge per query.

Per-module pricing means you only pay for the validation types you actually use. If your workflow only needs email validation, you are not subsidizing address or phone lookups. The pricing calculator on the pricing page shows exact per-credit costs by module and volume tier.

Paid credits (Verify credit packs) are valid for 1 year from the date of purchase. Credits are consumed as you use them — your balance carries forward and does not reset monthly. There is no auto-renewal and no recurring charge; when your credits run low, you purchase another pack at whatever volume tier fits your current needs.

The 1,000 free credits included at signup are valid for the 14-day free trial and expire at the end of the trial or when you upgrade to a paid plan, whichever comes first. That's 1,000 instead of the usual 100, for sign-ups until Nov 30, 2026. Free credits work identically to paid credits — same API, same validation quality, same response format — so your evaluation results are representative of production performance.

If you need to check your remaining balance, the DQVerify dashboard shows real-time credit usage broken down by module (address, email, phone) and by time period.

DQVerify is one platform for all three validation types — one API key and one account. Credits are bought in packs per check type and used one per call, so you only pay for the validations you actually run:

• 1 credit per address lookup — includes standardization with USPS CASS Certified software, ZIP+4 correction and DPV deliverability confirmation for US addresses, and a result code
• 1 credit per email check — includes MX record lookup, live SMTP handshake, disposable domain detection, and risk scoring
• 1 credit per phone lookup — includes carrier identification, line type classification, and active/ported status

Validating all three for one record takes three API calls and costs 3 credits (one per module). Each check type has its own credit pack, so you buy packs for the checks you run. The practical advantage is replacing 2–3 vendor integrations (typically Smarty for addresses, ZeroBounce for emails, Twilio Lookup for phones) with a single API key and a single account.

Enterprise is designed for organizations with high-volume needs (500,000+ validations per year), CRM connector requirements, or compliance demands that go beyond the self-serve Verify plan. It uses the same validation engine and API as every other tier — the difference is support, integrations, and contractual guarantees:

• Native CRM connectors — pre-built integrations for Salesforce, Shopify, and other platforms that validate records directly inside your existing workflows without custom API development
• Dedicated Customer Success Manager — a named contact who handles onboarding, monitors your usage patterns, and helps optimize your validation strategy across modules
• Custom SLA and uptime guarantees — contractual commitments beyond our 99.99% average uptime, including response time SLAs for support tickets
• Volume-tiered pricing — per-credit costs decrease at higher volume commitments, with pricing customized to your specific module mix and annual volume

Enterprise is not unlimited — it is priced based on volume and connector scope. Contact the team at support@dqverify.com to discuss your requirements and receive a custom quote.

DQVerify runs on two layers, and neither one keeps your validation data:

• The website, customer portal and account systems are hosted on Google Cloud in the United States (us-central1).
• Validation itself (address, email and phone checks) is performed by our affiliate DQE Software SAS on infrastructure in the European Union (France). Inputs travel over encrypted connections, are processed in real time, and are not retained once your request completes.
• Batch results are available for download during your session and are then deleted, whether or not you download them. Download your results before you leave the page.

DQE Software SAS, which develops and operates the validation technology, holds ISO/IEC 27001:2022 certification (BSI certificate IS 845668). DQVerify's Privacy Policy (effective September 16, 2026) describes what we collect, where it is processed, how long it is kept, and how to make a privacy request.