California, Pennsylvania, and Los Angeles All Changed Their Sales Tax Rules on October 1. Here's What Every Business Needs to Know
October 1, 2026 was the biggest single sales tax compliance day of Q4.
Five jurisdictions changed their rules simultaneously. California updated dozens of local jurisdictions. Los Angeles County added a half-cent from Measure ER. Pennsylvania began enforcing a fundamental sourcing change affecting Philadelphia and Pittsburgh. Texas updated local rates across cities and special districts. Utah added new emergency services taxes in two cities.
If you sell into any of these markets — from a storefront, an ecommerce platform, or a marketplace — your compliance setup changed on October 1. Here's every change, state by state.
Note: Washington D.C.'s planned rate increase from 6.5% to 7% was delayed by the D.C. Council to October 1, 2027. The current D.C. rate remains 6.5%. We covered that story separately in our Washington D.C. sales tax delay article.
California — 39 Local Rate Changes Including San Jose and Santa Clara County
California's quarterly rate update cycle hit October 1 with changes across dozens of jurisdictions — all flowing from voter-approved district tax measures from the June 2026 election.
As the CDTFA's Special Notice L-1037 confirmed, the affected jurisdictions include San Jose — California's third-largest city and the commercial hub of Silicon Valley — plus Milpitas, Los Gatos, Campbell, and unincorporated Santa Clara County. Additional cities across the state are also affected.
For ecommerce sellers shipping into California, this means the rate for some of your most important delivery addresses changed on October 1. If your tax software updates California rates automatically from the CDTFA's published tables, verify the update happened correctly. If you manage rates manually, download the updated CDTFA rate spreadsheet and update your configuration now.
California's economic nexus threshold is $500,000 in annual California sales. Sellers above that threshold are required to collect the correct rate for every California delivery address — including every October 1 change.
We covered the full California October 1 rate change breakdown in our dedicated California article.
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Los Angeles County — Measure ER Adds 0.5%
On top of California's standard quarterly rate update, Los Angeles County implemented the half-cent Measure ER increase that voters approved in June 2026.
As the City of West Hollywood confirmed in its official notice, the combined sales tax rate in West Hollywood increased from 10.5% to 11% on October 1 as a result of the new Los Angeles County sales tax approved by voters. The same pattern applies across LA County — the base countywide rate moved from 9.75% to 10.25%, with cities that already had their own local additions pushing above that.
For ecommerce sellers shipping to LA County addresses, this is the most significant California rate change of October 1. The Measure ER addition affects every taxable transaction delivered to any LA County address — not just unincorporated areas, but all 88 incorporated cities within the county.
We covered Measure ER's passage and full compliance implications in our LA County Measure ER article.
Pennsylvania — Philadelphia and Allegheny County Enforcement Begins
Pennsylvania's October 1 change is fundamentally different from a rate change — it's an enforcement flip that affects how local sales tax is sourced across the state.
Under Act 21 of 2026, Pennsylvania switched from origin-based to destination-based sourcing for Philadelphia and Allegheny County local taxes. As the Pennsylvania Department of Revenue's guidance confirmed, businesses outside Philadelphia that already collect Pennsylvania's 6% state tax must now also collect Philadelphia's 2% local tax when shipping taxable items to Philadelphia addresses. The same applies to Allegheny County's 1% local tax for deliveries to Pittsburgh addresses.
The law technically took effect January 1, 2026 — but the Department of Revenue gave businesses a grace period until October 1 to update their systems. That grace period ended October 1.
The combined rates now: 8% for Philadelphia deliveries, 7% for Allegheny County deliveries, and 6% for all other Pennsylvania addresses.
If you've been collecting 6% on all Pennsylvania deliveries regardless of destination, you've been under-collecting on Philadelphia and Pittsburgh orders. Update your systems now and review your historical collections for the January through September period.
We covered the full Pennsylvania Act 21 compliance guide in our dedicated Pennsylvania article.
Texas — Local Rate Changes Across Cities and Special Districts
Texas updates its local rates quarterly — and October 1 brought a fresh wave of city and special district changes across the state.
As the Texas Comptroller's October 2026 rate change bulletin confirmed, multiple Texas cities and special purpose districts implemented new or adjusted rates effective October 1. The Texas Comptroller's office publishes updated rate tables quarterly — the Q4 2026 tables are now the authoritative source for any Texas delivery address.
For ecommerce sellers shipping into Texas, verify your tax software has pulled the updated Q4 2026 Texas rate tables. If you manage Texas rates manually, download the current tables from the Texas Comptroller's website and update your configuration for all affected jurisdictions.
Utah — New Emergency Services Taxes in Two Cities
Utah's October 1 update is smaller in scope but worth knowing for businesses with Utah customer concentration.
Per the Utah State Tax Commission's October 2026 tax bulletins, Washington City and Hildale in Washington County both imposed new 0.33% Emergency Services Taxes effective October 1, 2026. Both cities are in the fast-growing St. George metro area of southwestern Utah.
For sellers with customers in Washington City or Hildale specifically, the combined rate increased by 0.33 percentage points from October 1. Verify your tax software reflects the updated rates for these ZIP codes.
The Compliance Checklist for October 1 Changes
If you haven't already updated your systems for these changes, here's the action list.
Verify your California rates reflect the CDTFA's L-1037 changes. Pull the updated rate spreadsheet from the CDTFA's website and confirm your tax software has applied the correct October 1 rates for San Jose, Milpitas, Campbell, Los Gatos, and Santa Clara County unincorporated areas.
Verify your LA County rate reflects Measure ER. The base LA County rate is now 10.25% — higher in cities with their own additional local taxes. Confirm your system applies the correct combined rate for each LA County delivery address.
Update your Pennsylvania sourcing for Philadelphia and Allegheny County. Every Philadelphia delivery is now 8%. Every Allegheny County delivery is now 7%. If you've been collecting 6% on all Pennsylvania orders, update immediately.
Pull the Q4 2026 Texas rate tables. Verify your Texas rates reflect the October 1 quarterly update for all affected cities and special districts.
Update Washington City and Hildale Utah rates if you have customer concentration there. The 0.33% emergency services tax is new as of October 1.
One More Thing — Indiana's Gas Tax Suspension
While not an October 1 change, Indiana's gas tax suspension expires October 5 — just four days away. Governor Braun has said he will reevaluate around that date. If he doesn't extend, Indiana pump prices jump approximately 60 cents per gallon immediately. We covered the full Indiana gas tax story in our dedicated Indiana gas tax article.
Not sure whether your systems reflect all of the October 1 changes — or concerned you've been under-collecting on Philadelphia, LA County, or Pennsylvania transactions? Book a free consultation with our team at sales.tax. We'll audit your rate setup across every affected jurisdiction and make sure you're collecting correctly going forward.
What this means for your business
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