Technical guides for USPS v3 REST migration, address validation, rate limits, pricing comparisons, and shipping workflow architecture.https://revaddress.com/en-ushttps://revaddress.com/blog/how-to-find-hs-code-for-anything-you-ship/https://revaddress.com/blog/how-to-find-hs-code-for-anything-you-ship/A three-minute method for finding the right HS, HTS, or Schedule B code: five worked examples from the live US tariff schedule, plus the fields USPS validates.Tue, 18 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-pricing-2026-what-it-really-costs/https://revaddress.com/blog/usps-api-pricing-2026-what-it-really-costs/USPS address validation stopped being free on August 1, 2026. The published fee curve, the license that gates it, and what direct-vs-third-party actually costs at four volumes.Tue, 18 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-rate-limits-2026-what-changed/https://revaddress.com/blog/usps-api-rate-limits-2026-what-changed/USPS v3 throughput fell from roughly 6,000 requests per minute on Web Tools to 60 per hour. What changed, what it does to checkout at peak, and five architecture patterns with working code.Tue, 18 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/usps-crid-mid-enrollment/https://revaddress.com/blog/usps-crid-mid-enrollment/Step-by-step USPS CRID registration, Mailer ID (MID) enrollment, EPA setup, COP claims linking, and the Addresses API license that has gated address validation since August 1, 2026.Tue, 18 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-shutdown-2026/https://revaddress.com/blog/usps-web-tools-shutdown-2026/USPS retired the Web Tools XML API on January 25, 2026. See what broke, which platforms were affected, and the fastest migration path to the v3 REST API.Tue, 18 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/experian-address-validation-vs-revaddress/https://revaddress.com/blog/experian-address-validation-vs-revaddress/Experian's Address Validate API (formerly QAS Pro On Demand) is quote-only and sized for a 250-country data-quality suite. What a US team actually pays for, what it gets instead on a flat published price, and a one-afternoon migration.Mon, 10 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/postgrid-vs-revaddress/https://revaddress.com/blog/postgrid-vs-revaddress/PostGrid vs RevAddress for USPS address validation. Pricing tiers, batch support, and where validation-only stops and the full USPS shipping stack begins.Mon, 03 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/loqate-vs-revaddress/https://revaddress.com/blog/loqate-vs-revaddress/Loqate bills US address verification in per-lookup credits behind a sales quote. What that costs at every volume, what a flat USPS-native price looks like beside it, and how to move the US traffic in an afternoon.Mon, 13 Jul 2026 00:00:00 GMThttps://revaddress.com/blog/melissa-address-verification-vs-revaddress/https://revaddress.com/blog/melissa-address-verification-vs-revaddress/Melissa bills address verification in credits — and a single US address costs 3 of them, so the headline $0.003 rate is really ~$0.009 per lookup. Here's the real per-lookup math at every tier, and a flat-rate USPS-native migration path.Mon, 29 Jun 2026 00:00:00 GMThttps://revaddress.com/blog/lob-vs-revaddress/https://revaddress.com/blog/lob-vs-revaddress/Lob vs RevAddress for US address validation. Real 2026 pricing at every tier, DPV code depth, code samples, and why USPS-shipping teams overpay on a direct-mail platform.Mon, 22 Jun 2026 00:00:00 GMThttps://revaddress.com/blog/google-address-validation-api-vs-revaddress/https://revaddress.com/blog/google-address-validation-api-vs-revaddress/Google's Address Validation API costs $17 per 1,000 requests after a 5,000-call free tier — and it isn't full USPS CASS-certified. Here's the real cost at scale, the deliverability gap, and a flat-rate migration path.Mon, 15 Jun 2026 00:00:00 GMThttps://revaddress.com/blog/checkout-guard-widget/https://revaddress.com/blog/checkout-guard-widget/Add real-time address validation and fraud-risk review to address forms with one script tag. WooCommerce, Shopify account forms, Magento, custom forms. Free tier.Wed, 15 Apr 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-march-2026-migration/https://revaddress.com/blog/easypost-march-2026-migration/EasyPost's March 17, 2026 enforcement is live. See what changed, the Free Access vs BYOCA cost impact, and flat-rate alternatives after enforcement.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shipping-api-comparison-2026/https://revaddress.com/blog/shipping-api-comparison-2026/Compare EasyPost, Shippo, ShipEngine, and RevAddress for USPS. Pricing, code samples, migration cost. 2026 numbers.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-migration-guide/https://revaddress.com/blog/usps-migration-guide/Step-by-step USPS Web Tools migration guide covering endpoint mapping, OAuth setup, rate-limit handling, and working v3 REST code samples.Tue, 17 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/smarty-vs-revaddress/https://revaddress.com/blog/smarty-vs-revaddress/Detailed comparison of Smarty and RevAddress for USPS address validation. Pricing, batch support, caching, and API design compared side-by-side.Thu, 12 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-march-17-deadline-migration-options/https://revaddress.com/blog/easypost-march-17-deadline-migration-options/EasyPost's March 17 plan enforcement is live. Migration options with cost savings at 1K-50K labels/mo, code examples, and a 5-step checklist.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-vs-revaddress/https://revaddress.com/blog/easypost-vs-revaddress/Factual pricing comparison between EasyPost and RevAddress for USPS shipping APIs. Per-label vs flat pricing math, feature comparison, and when each wins.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/magento-usps-ac15210-fix/https://revaddress.com/blog/magento-usps-ac15210-fix/Magento's built-in USPS module broke when Web Tools retired. Drop-in v3 REST fix you can ship in one afternoon. Every step, working code.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shipengine-vs-revaddress/https://revaddress.com/blog/shipengine-vs-revaddress/ShipEngine vs RevAddress for USPS shipping. Pricing tiers, API design, code samples, and when to pick each. Zero marketing fluff.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shippo-vs-revaddress/https://revaddress.com/blog/shippo-vs-revaddress/Head-to-head: Shippo vs RevAddress for USPS shipping. Pricing at every volume, architecture, code samples, when to pick each.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-access-control-april-2026/https://revaddress.com/blog/usps-api-access-control-april-2026/USPS launches API Access Control in April 2026, restricting tracking data access. What changes, who is affected, how to prepare.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-api-package-replacement/https://revaddress.com/blog/usps-api-package-replacement/The usps-api PyPI package and usps-webtools / usps-webtools-promise npm packages are dead. Here are the working 2026 replacements.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-april-2026-access-control-changes/https://revaddress.com/blog/usps-april-2026-access-control-changes/USPS is restructuring API access control in April 2026 — the second wave of breaking changes. Why migrate now, not later.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-batch-address-validation-api/https://revaddress.com/blog/usps-batch-address-validation-api/Validate up to 50 US addresses in a single API call. Parallel processing, 24-hour cache, webhook results. Integration in minutes.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-oauth-troubleshooting/https://revaddress.com/blog/usps-oauth-troubleshooting/401s, 403s, or token refresh failures from USPS v3? This guide covers every OAuth error with fix recipes. CRID, MID, EPA setup.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-address-validation-quickstart/https://revaddress.com/blog/usps-v3-address-validation-quickstart/Validate a US address with the USPS v3 REST API in one curl command. Working code for Python, Node.js, and curl — no XML, no USERID, no middleman.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-migration-guide-nodejs-python/https://revaddress.com/blog/usps-v3-migration-guide-nodejs-python/Step-by-step migration from USPS Web Tools XML to v3 REST using the usps-v3 Python and Node SDKs.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-node-quickstart/https://revaddress.com/blog/usps-v3-node-quickstart/Install the usps-v3 Node SDK. Validate addresses and track packages in minutes. TypeScript first, zero dependencies.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-php-quickstart/https://revaddress.com/blog/usps-v3-php-quickstart/Install the revaddress/usps-v3-php Composer package. Validate addresses, track packages, and run labels in PHP. Works with Magento, WooCommerce, Laravel.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-python-quickstart/https://revaddress.com/blog/usps-v3-python-quickstart/Install the usps-v3 Python SDK and start validating addresses, tracking, and comparing rates.ping rates in minutes. Full code examples with type hints.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-sdk-comparison/https://revaddress.com/blog/usps-v3-sdk-comparison/usps-v3 SDK for Python, Node, and PHP. Automatic OAuth, validation, tracking, rates, and labels. MIT licensed, production-tested.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-endpoint-mapping/https://revaddress.com/blog/usps-web-tools-endpoint-mapping/Definitive USPS Web Tools XML to v3 REST mapping across addresses, tracking, labels, pricing, and locations.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-migration-checklist/https://revaddress.com/blog/usps-web-tools-migration-checklist/Step-by-step checklist for migrating from USPS Web Tools XML to the v3 REST API. OAuth, endpoint mapping, error handling.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/woocommerce-usps-migration/https://revaddress.com/blog/woocommerce-usps-migration/Replace your broken WooCommerce USPS shipping plugin with RevAddress v3 REST in one afternoon. Every hook, working code.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-rate-limits/https://revaddress.com/blog/usps-rate-limits/Practical strategies for handling USPS v3 API rate limits. Caching, batching, queue architecture, and BYOK for production workloads.Mon, 09 Mar 2026 00:00:00 GMT