Overview

Lob corrects and standardizes address records to help determine whether they can be delivered. Website checks can complete and correct an address as a customer enters it, while the API handles individual and bulk validation. Results can add ZIP+4, carrier route, address type, latitude, and longitude, making the service useful for both data cleanup and downstream postal or geographic decisions.

Coverage spans more than 240 global territories, and U.S. verification is USPS CASS certified. Lob also provides a confidence score based on its mail delivery data to over half of U.S. households. These capabilities make it a more substantial choice than a basic formatting check, particularly for organizations that need delivery signals as well as normalized records.

Key features

Entry-time correction: Completing and standardizing addresses on a website can catch mistakes before they become part of a customer record. This is most useful where address entry is a frequent part of a sign-up or checkout flow.
Individual and bulk API checks: The API supports both one-off validation and batch work, so teams can handle incoming records as well as existing lists without relying on separate validation modes.
Postal and geographic enrichment: ZIP+4, carrier route, address type, latitude, and longitude can support mailing decisions and location-based uses beyond simple correction.
Developer and integration options: The interactive demo provides examples in cURL, TypeScript, Node, Ruby, Python, PHP, Java, Elixir, and C#. Lob also lists AV Elements, Shopify Address Cleanser, Airtable Address Cleanser, and Zapier integrations, which gives teams several routes to connect the service.
Security and compliance: Lob says it encrypts data in transit with TLS 1.2+ and at rest with AES-256, and provides automatic redaction and retention policies. It aligns with SOC 2 and HIPAA, supports GDPR and CCPA/CPRA, and completes annual SOC 2 Type 2 audits. These controls are relevant for teams handling sensitive records, though they do not remove the need to assess fit against an organization’s own requirements.

Pricing

Lob uses a freemium model, with a Developer tier at 0.00 USD per month and paid plans from $20/mo (annual). The Developer tier has no subscription fee, but its allowance is not a promise of unlimited validation: it includes up to 6,000 mailings, one user, and charges $0.05 per additional U.S. address verification or $0.07 per additional international verification. It suits a solo developer or small project beginning with limited usage, but added verification costs can matter once usage exceeds the included terms.

Startup — 260.00 USD per month: Includes up to 75,000 mailings and three users. The plan includes 1,000 U.S. verifications for $25/mo, then $0.025 per additional verification; 500 international verifications are included for $30/mo, then $0.06 each. It raises capacity beyond Developer, but the separate verification charges and bundled mailing allowance mean it is best judged against both address-check volume and mailing needs.
Growth — 550.00 USD per month: Includes up to 150,000 mailings and five users, with 50,000 U.S. verifications included for $450/mo, then $0.009 each; 10,000 international verifications are included for $550/mo, then $0.055 each. Its larger included verification volumes and lower additional U.S. rate suit heavier operations, but the monthly costs and separate international charge are substantial.
Enterprise — custom pricing: For 150,000+ mailings/year and 20+ users, it offers address verification pricing on request, advanced support, account management, and integration assistance. This is the relevant route for larger teams that need those support services; it does not provide a public price for direct comparison.

The pricing page also offers a 30-day Enterprise free trial for high-volume senders; print and postage are billed separately at discounted Enterprise rates. Standard support is included for Developer, Startup, and Growth, while Enterprise adds account management and integration assistance. The plan descriptions tie capacity to mailings, seats, and verification volume, so buyers should compare all three against expected use rather than treating the monthly plan price as the full cost of address checks.

Platforms

Lob supports web and API access. The API and broad code examples favor teams able to integrate address validation into software, while the web option provides another way to work with the service.

Who it's for

Lob is a good fit for businesses that need to correct addresses at entry, clean existing lists in bulk, or use postal and geographic details in delivery workflows. Its coverage and U.S. certification make it relevant to international address operations as well as U.S. mailing programs. It is less compelling for a team seeking only occasional low-cost checks without mailing capacity or a need for API integration, because plan economics combine those elements with usage-based verification fees.

Pros and cons

Pro: Real-time correction and bulk API validation cover both prevention of bad entries and cleanup of existing data.
Pro: Postal enrichment and a confidence score add delivery context beyond standardized address formatting.
Pro: More than 240 territories and USPS CASS certification support broad coverage with a specific U.S. validation credential.
Con: Verification can cost extra beyond included allowances, and plan prices also correspond to mailing volumes and user counts, making total cost dependent on several usage dimensions.
Con: Developer is limited to one user and 6,000 mailings, while moving up requires materially higher monthly commitments; larger-scale buyers must request Enterprise pricing.

Alternatives

If the primary need is broader direct-mail campaign software rather than address verification, compare Direct Mail Automation Software. For creating postcards, Postcard Maker Software is the more relevant category; for comparing address-checking products, see Address Verification Software.

DocuPost is a freemium API and web option whose Free plan allows letters and postcards with no send limits but charges per mailpiece, adds DocuPost branding to the cover letter, and retains items for 90 days. Choose it when sending those mailpieces matters more than Lob’s address-verification and enrichment features.

Inkit is a freemium API and web service with a free plan limited to three signature requests per month, one seat, and 10GB of storage. It is a better match when signature requests and document storage are the priority rather than address validation.

Postalytics offers a free plan with unlimited campaigns, templates, and lists, one login, and per-piece mail charges; its basic integrations exclude Salesforce and HubSpot Premium. Choose it when campaign execution is the focus and those integration limits are acceptable.

PostPilot has a free start with payment only for postcards and postage, plus the full platform and 10+ analytics reports. It is worth considering when postcard sending and campaign analytics are a closer fit than address verification.

Sincerely provides a free Audit plan for CRM or CSV imports, mailability audits, brand materials, and draft editing, but that plan cannot mail. It suits teams that want to audit and prepare mail before committing to sending.

Stannp has a free plan with one user, one template, 50,000 contacts, and 20 virtual printer items per month, with no minimum or maximum send volume. It may suit a small direct-mail operation that values contact capacity and virtual printer items over Lob’s validation focus.

thanks.io offers a pay-as-you-go plan with no monthly subscription fee and full API access; gift cards require Business, Professional, or Enterprise. It is a relevant alternative when avoiding a subscription and retaining API access are the priorities.

MailStream is another freemium API and web option to consider.

Verdict

Choose Lob Address Verification if your team needs address correction at entry, bulk validation, and delivery-oriented postal or geographic data across a broad territory set. Its API, U.S. certification, and enrichment make a strong case for operational address hygiene. Look elsewhere if you need only occasional inexpensive checks or want pricing centered solely on verification: Lob’s mailing allowances, seats, and additional verification charges all shape the bill.

	Lob Address Verification	USPS Addresses API
Free plan	Yes
Free trial	Yes
Paid from	$260/mo
Platforms	api, Web	api
Free plan	Yes	No
Paid from	20 /mo
API access	Yes	Yes
Batch validation	Yes
Address correction	Yes	Yes
Address standardization	Yes	Yes
Address autocomplete	Yes
International coverage	global	local

Lob Address Verification vs USPS Addresses API

Lob Address Verification

USPS Addresses API