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/2026-redistricting-address-files/https://revaddress.com/blog/2026-redistricting-address-files/The Census Bureau's official district files arrive in September, weeks before the year's heaviest political mail. What that means if you mail by district.Fri, 21 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/new-congressional-maps-2026/https://revaddress.com/blog/new-congressional-maps-2026/Every state with a new U.S. House map for 2026: how each was adopted, when it was enacted, and where the litigation stands, with official sources.Fri, 21 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/north-carolina-new-congressional-map-2026/https://revaddress.com/blog/north-carolina-new-congressional-map-2026/SL 2025-95 redrew North Carolina's U.S. House map for 2026. What moved in the First and Third Districts, the litigation, and the voting calendar.Fri, 21 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/what-congressional-district-am-i-in/https://revaddress.com/blog/what-congressional-district-am-i-in/How to look up your congressional district, and why in the states that redrew for 2026 the district you are in and the district you vote in differ.Fri, 21 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/where-do-i-vote-texas-new-map/https://revaddress.com/blog/where-do-i-vote-texas-new-map/Your Texas polling place is set by your county, not the congressional map. What PLANC2333 changes on your November ballot, and how to check it.Fri, 21 Aug 2026 00:00:00 GMThttps://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: worked examples from the live US tariff schedule and the fields USPS validates.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 is quote-only: 1 credit per successful lookup, price on request. What to ask for, and what published flat pricing buys.Mon, 10 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/postgrid-vs-revaddress/https://revaddress.com/blog/postgrid-vs-revaddress/PostGrid bills US address verification from $18 a month with a per-lookup geocoding surcharge. What it includes, what it does not, and where each one fits.Mon, 03 Aug 2026 00:00:00 GMThttps://revaddress.com/blog/loqate-vs-revaddress/https://revaddress.com/blog/loqate-vs-revaddress/Loqate publishes 4.1 to 4.7 cents a lookup for US address capture and quotes verification on request. What that costs at volume, against a flat plan.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 US address verification in credits: 3 per address, so a $40 pack of 10,000 credits is about 3,300 lookups. The real per-lookup math for 2026.Mon, 29 Jun 2026 00:00:00 GMThttps://revaddress.com/blog/lob-vs-revaddress/https://revaddress.com/blog/lob-vs-revaddress/Lob's cheap verification bundles ride direct-mail plans that start at $260/mo. The published August 2026 rates, DPV depth, and when each is right.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 calls after 5,000 free, and its terms cap caching at 30 days. The real curve, and when flat pricing wins.Mon, 15 Jun 2026 00:00:00 GMThttps://revaddress.com/blog/checkout-guard-widget/https://revaddress.com/blog/checkout-guard-widget/One script tag adds inline address checking to any address form you control. The real contract: attributes, badge states, sandbox keys, and how it fails.Wed, 15 Apr 2026 00:00:00 GMThttps://revaddress.com/blog/smarty-vs-revaddress/https://revaddress.com/blog/smarty-vs-revaddress/Smarty's US Address Verification runs $17 to $485 a month by volume, checked August 2026. What that buys, and what a flat USPS-native plan costs instead.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 auto-enrolled accounts on March 17, 2026. What Free Access and BYOCA actually cost at volume, and how to decide which one you should be on.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-march-2026-migration/https://revaddress.com/blog/easypost-march-2026-migration/The endpoint mapping, working code, and BYOK setup for moving USPS address validation, rates, tracking and labels off EasyPost. Plus the USPS license step.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/easypost-vs-revaddress/https://revaddress.com/blog/easypost-vs-revaddress/EasyPost gives you 3,000 free labels and 100+ carriers. RevAddress is flat-rate and USPS-only. Where the crossover sits, and what each bill actually covers.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/magento-usps-ac15210-fix/https://revaddress.com/blog/magento-usps-ac15210-fix/AC-15210 is Adobe's official USPS REST patch, not an unfixed bug. How to apply it, the config.xml error it ships with, and the gaps it leaves behind.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shipengine-vs-revaddress/https://revaddress.com/blog/shipengine-vs-revaddress/ShipEngine is becoming ShipStation API. The published August 2026 plans, the per-endpoint quota most comparisons miss, and when each is right.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shipping-api-comparison-2026/https://revaddress.com/blog/shipping-api-comparison-2026/EasyPost, Shippo, ShipEngine and RevAddress compared on August 2026 published rates. Three different billing units, the USPS fee underneath, and who wins.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/shippo-vs-revaddress/https://revaddress.com/blog/shippo-vs-revaddress/Shippo bills $0.07 a label and $0.02 an address validation as of August 2026. What that costs at volume against a flat plan, and when Shippo wins.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 switched tracking from possession-based to identity-based access on April 1, 2026. What landed, who it hit, and how it led to the August license.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, usps-webtools, and usps-webtools-promise packages target an API that no longer exists. The errors you are seeing, and the one-command swap.Tue, 10 Mar 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 costs.Tue, 10 Mar 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 a minute on Web Tools to 60 per hour. What that does to checkout at peak, and five architecture patterns.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/Access Control landed April 1 and the license regime followed on August 1. The integration shape that absorbed both, and the checks to run now.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 50 US addresses in one request. The exact payloads, per-address failure handling, rate-limit backoff, and how to run a 10,000-row list through it.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-crid-mid-enrollment/https://revaddress.com/blog/usps-crid-mid-enrollment/Where the CRID and MID come from, the EPA that pays for labels, the COP screen that links them, and the Addresses API license required since August 1, 2026.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-oauth-troubleshooting/https://revaddress.com/blog/usps-oauth-troubleshooting/401, 403, and 429 from USPS v3, with the exact fix for each, including the Addresses API license that has gated address calls since August 1, 2026.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/The USPS v3 address call in curl, Python and Node: OAuth, the required parameters, every DPV code, and the license USPS has required since August 1, 2026.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/Every Web Tools operation rewritten in the usps-v3 Python and Node SDKs, with the exact method names, the field that silently fails, and a cutover playbook.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-node-quickstart/https://revaddress.com/blog/usps-v3-node-quickstart/Install usps-v3, authenticate once, and call address validation, tracking, rates, and labels from Node. Zero dependencies, typed errors, Express route.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-php-quickstart/https://revaddress.com/blog/usps-v3-php-quickstart/Install revaddress/usps-v3-php and call the USPS v3 REST API from PHP: validation, tracking, rates, labels, plus Magento, WooCommerce and Laravel wiring.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-python-quickstart/https://revaddress.com/blog/usps-v3-python-quickstart/Install usps-v3, authenticate once, and call address validation, tracking, and rates from Python. Working code, real return shapes, typed errors.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-v3-sdk-comparison/https://revaddress.com/blog/usps-v3-sdk-comparison/The usps-v3 SDKs for Python and Node.js at v1.0.4. Real method signatures, which calls need Payment Authorization, error classes, and token handling.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/Every Web Tools XML API mapped to its v3 REST route, with the auth change, the reversed address fields, and the gotchas that break production migrations.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/A numbered checklist for moving off USPS Web Tools XML: endpoint map, the license now required, OAuth, field mapping, error mapping, and the cutover.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-web-tools-shutdown-2026/https://revaddress.com/blog/usps-web-tools-shutdown-2026/secure.shippingapis.com returns errors for every call since January 25, 2026. What broke (WooCommerce, Magento, Stamps.com) and the migration path to v3.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/woocommerce-usps-migration/https://revaddress.com/blog/woocommerce-usps-migration/USPS Web Tools died January 25, 2026. Update the official extension to 5.2.5, enter REST credentials, and handle the 60-per-hour cap it does not cache.Tue, 10 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-migration-guide/https://revaddress.com/blog/usps-migration-guide/Every Web Tools endpoint mapped to its v3 REST equivalent, the OAuth flow in three languages, the field swap that corrupts addresses, and the 60/hr wall.Mon, 09 Mar 2026 00:00:00 GMThttps://revaddress.com/blog/usps-rate-limits/https://revaddress.com/blog/usps-rate-limits/USPS v3 allows 60 requests an hour per app, shared across every endpoint. Caching, queue smoothing, the increase request, and BYOK, with working code.Mon, 09 Mar 2026 00:00:00 GMT