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'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-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, 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/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 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-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/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 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/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 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/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/Step-by-step USPS Web Tools migration guide covering endpoint mapping, OAuth setup, rate-limit handling, and working v3 REST code samples.Mon, 09 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