Frequently Asked Questions

DQE is a US data validation platform that verifies postal addresses, email addresses, and phone numbers through a single integration — one API key, one endpoint, one unified JSON response.

Unlike traditional validation vendors that require procurement cycles, SFTP file transfers, and enterprise contracts, DQE is fully self-serve: sign up with a business email, receive 100 free validations, and start immediately — no credit card, no sales call.

• Address validation — USPS CASS-certified standardization and DPV deliverability confirmation
• 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 a 99.99% uptime SLA and US data residency.

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

• Address — standardizes to USPS format, confirms deliverability via DPV, appends ZIP+4, county, and RDI (Residential Delivery Indicator)
• 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

Submitting all three in one API call costs 3 credits (one per module), but requires only one API key and one integration.

Yes. DQE is a USPS CASS (Coding Accuracy Support System) certified address validation provider through a licensed OEM partnership.

CASS certification applies to batch CSV processing jobs — meaning batch output qualifies for USPS compliance programs such as nonprofit postal discounts.

Individual real-time API calls return USPS DPV (Delivery Point Validation) confirmation — the same deliverability check — but are not independently CASS-certified per USPS program definitions.

Beyond the core address, email, and phone modules, DQE 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, longitude, and county data to validated addresses

Contact the team for specifics on any module.

DQE Standalone is the web-based platform version of DQE — 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

DQE 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 — DQE's key differentiator is one integration, not one shared credit. A single POST to /validate can include an address, an email, and a phone number, and DQE returns results for all three in one JSON response, typically 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)

DQE 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:

• Standardized address in USPS format (all-caps, abbreviated directionals and street suffixes)
• ZIP+4 code (if the address is deliverable)
• DPV status — deliverable, vacant, or non-delivery point
• County name and FIPS code
• RDI flag — residential or commercial
• Standardized unit/secondary address component (if provided)

For undeliverable inputs, DQE returns a structured error code explaining why — street not found, city/state/ZIP mismatch, missing unit number, etc. The response schema is consistent across all outcomes.

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

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

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

Smarty validates addresses only. DQE validates addresses, emails, and phone numbers through a single integration — one API key replaces 2–3 vendors.

On address validation specifically, both platforms deliver:

• USPS DPV confirmation
• ZIP+4 appending
• County data
• 240+ countries for international addresses

DQE additionally returns RDI (Residential Delivery Indicator) and structured validation flags. Migration from Smarty is typically a one-line base URL swap — DQE's address endpoint accepts the same input fields as Smarty's US Street Address API.

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 100 free validations immediately.
• 2. Copy your API key from the dashboard.
• 3. Send a POST request to /validate with any combination of address, email, and phone fields. 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 a consistent response schema across all three validation types.

Yes — DQE 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

Batch output runs through DQE's CASS-certified address validation engine, so it qualifies for USPS compliance programs. Available on Verify and Enterprise plans.

DQE offers three tiers — no monthly subscription on any plan:

• Validate (free) — 100 credits at signup, no credit card required
• Verify — one-time credit purchase starting at $700 for 20,000 credits, with volume tiers up to 500,000. Pricing varies by module. Credits valid for 1 year.
• Enterprise — for CRM connectors or volumes above 500,000. Custom pricing, contact the team.

Each module draws on a different licensed data source with its own cost structure:

• Address — USPS CASS-certified data licensed via a federally regulated dataset
• Email — live SMTP infrastructure and continuously updated disposable-domain and spam-trap databases
• Phone — real-time carrier network lookups for line-type identification

Per-module pricing reflects the actual cost of each data source rather than bundling everything into a flat rate.

Paid credits (Verify plan packs and pay-as-you-go top-ups) 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.

The 100 free credits included at signup expire after 12 months or upon upgrade to a paid plan, whichever comes first.

DQE is one platform for all three tools — one API key, one endpoint, one unified JSON response. Billing is per module per call:

• 1 credit per address lookup
• 1 credit per email check
• 1 credit per phone lookup

Submitting all three in one request costs 3 credits. Your balance is shared across all modules — no siloed pools. The advantage is one integration instead of managing separate API keys, billing accounts, and response schemas for each vendor.

Enterprise is for organizations with high-volume needs (500,000+ validations), CRM connector requirements, or compliance demands. It includes:

• Native CRM connectors — Salesforce, Shopify, and others
• Dedicated Customer Success Manager
• Custom SLA and uptime guarantees
• Volume-tiered pricing

Enterprise is not unlimited — it is priced based on volume and connector scope. Contact the team to discuss your requirements.

Yes. DQE maintains full US data residency:

• All validation inputs (addresses, emails, phone numbers) are processed on US infrastructure
• All validation outputs are stored exclusively in the United States
• No customer data is transferred to servers outside the US as part of the core validation workflow

DQE is also ISO 27001 certified, confirming that its information security management practices meet the international standard. This applies to customers subject to CCPA and other US state privacy laws. DQE's Privacy Policy (effective May 11, 2026) describes the full data retention framework.