Changelog

September 17, 2026

Rate data

• DataRates now refresh daily instead of weekly. The full fetch runs every day at 09:00 UTC, after midnight in every US time zone. Previously it ran only on Sundays, so a rate taking effect on a quarter boundary could be up to several days late. October 1 changes now apply on October 1.
• FixAlaska: ZIPs not covered by the Alaska Remote Seller Sales Tax Commission were being given the statewide local average of 1.82%. Anchorage and Fairbanks levy no sales tax and now correctly return 0%, marked estimated. Municipalities with a real local tax, such as Juneau and Kenai, are unchanged and remain authoritative.
• FixNevada: the statewide 6.85% base was being folded into the county component, so component breakdowns did not reflect how Nevada levies the tax, and counties absent from the source file could publish a combined rate below the state minimum. Components are now split correctly and no row can fall below its state's base rate. Combined totals for covered ZIPs were already correct and did not change.
• DataStatewide base rows restored. GET /rates?state=XX and GET /rates/states now cover all 51 jurisdictions. Nevada had been missing.

API

• APIErrors are no longer metered. Requests rejected for a client error, and any request that fails on our side, are refunded to your monthly quota. Only requests we actually serve count. Quota 429s are the one exception.
• APIZIP+4 accepted. /rates and /calculate now take either a 5-digit ZIP or ZIP+4, using the first five digits. A malformed ZIP returns a clear 400 instead of a misleading "no rate found".
• APICounty lookups work. ?state=CA&county=Los+Angeles previously returned 404 in nearly every state. It now resolves to the county-level rate and reports which ZIP row answered.
• FixUnknown product categories are rejected. A misspelled category on a line item used to fall through to being taxed at the full rate. It now returns 400 listing the valid categories.

Documentation

• DocsNew quickstart covering the path from a fresh key to a recorded sale, with examples in curl, Python and Node.js. See Quickstart.
• DocsNew Keys & security section explaining why API keys must stay server-side and why browser calls are blocked by design. See Keys & security.
• DocsTransactions, Reports and Usage are now documented. These endpoints already existed but were missing from the reference.
• DocsVersioning guidance: pin new integrations to the /v1 prefix.
• FixThe /rates example response had components that did not sum to its stated total, and labelled an estimated source as authoritative. Replaced with real API output, plus a table explaining what rate_type, effective_date, updated_at and all_jurisdictions actually mean.
• DocsRate-limit and request-id response headers are now documented, along with the base URL api.sefro.app, which had been shown inconsistently.

September 6, 2026

• FixIncorrect statewide rates on state guide pages. Nevada, Alabama, Idaho and New Mexico published wrong base rates, derived from an unreliable column rather than an authoritative table. Corrected, with a validation guard so a missing or zero base can no longer be published.
• APIAccount page added for usage, billing management and self-serve API-key re-issue.
• APITrial entitlement enforced at the advertised 10,000 requests, tracked separately from the plan quota it converts to.
• DocsPricing, quotas and plan figures aligned across the site, documentation and checkout.

September 1, 2026

• APIGET /usage — check your own consumption, remaining allowance, overage and reset date.
• APISelf-serve key re-issue. Replace a lost or exposed key without contacting support; the old key stops working immediately.

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