Insights for Modern CPA Firms

Tennessee Franchise and Excise Tax: Complete 2025 Guide

Tennessee has no individual income tax but every business must file Form FAE 170 covering both franchise and excise tax by April 15. Complete 2025 Tennessee business tax guide with sample calculations.

Jun 29, 2026 4 min

State Tax Conformity: 7 Essential Issues for CPA Firms

State tax conformity issues create silent errors in multi-state returns. Here are 7 federal-state mismatches your firm needs to track for every client filing across state lines.

Jun 23, 2026 7 min

North Carolina Sales Tax County Rates: 5 Essential Rules for CPA Firms

North Carolina's sales tax starts at 4.75% state and goes up based on which county your customer is in. Here are 5 essential rules for getting the county rate right, handling qualifying food, and filing Form E-500.

Georgia Sales Tax Economic Nexus: 5 Essential Rules for CPA Firms

Georgia's $100K-or-200-transaction economic nexus standard applies on an 'or' basis with a calendar-year lookback. Here are 5 essential rules CPA firms need for threshold tracking, marketplace facilitator exclusions, local option tax rates, and Form ST-3 prep.

Pennsylvania CNIT Phase Down Planning: 5 Essential Rules for CPA Firms

Pennsylvania CNIT drops from 7.49% in 2026 to 4.99% by 2031. Here are 5 essential rules CPA firms need for income timing, NOL utilization, apportionment strategy, and Form RCT-101 prep during the phase-down.

California Mandatory E File Threshold: 5 Essential Rules for CPA Firms

California's FTB e-file mandate applies to preparers who filed more than 100 individual returns in any calendar year. Paper filing without a valid opt-out triggers a $50 per-return penalty. Here are 5 essential rules.

Jun 22, 2026 7 min

New York S-Corp Election: 4 Critical CT-6 Rules CPAs Must Know

A federal S election does not automatically apply for New York. Form CT-6 must be filed separately, all shareholders must consent, and NYC taxes S-corps as C-corps regardless. Here are the four rules that determine whether your clients' elections hold.

Florida Sales Tax Filing Schedule: 4 Critical DR-15 Rules

Florida sales tax is due the 20th of the month, but the electronic payment deadline is actually 5 p.m. the day before. Here are the 4 DR-15 rules that determine your clients' filing cadence, collection allowance, and surtax obligations.

Illinois PTET Election: 4 Essential Rules on PPRT, Estimates, and Credits

Illinois PTET election stacks on top of the personal property replacement tax, and the estimated payment base combines both. Here is the election math, PPRT interaction, and credit flow on partner returns.

California Business Estimated Tax: Complete 2026 Guide

California's 30/40/0/30 estimate schedule and mandatory e-pay rules catch businesses migrating from other states. Here's the safe harbor calculation, Form 100-ES vs 540-ES breakdown, and underpayment penalty guide for CPA firms.

North Carolina Corporate Tax Phase Out: 5 Essential Planning Rules

North Carolina's corporate income tax is falling to 0% by 2030. Here are 5 essential planning rules CPA firms need to advise C-corp and pass-through clients on the rate curve.

Georgia PTET Election: 5 Essential Rules for CPA Firms

Georgia PTET election mechanics include a retroactive window on the extended return, a non-refundable credit for owners, and a SALT math picture that shifted under OBBBA. Here are 5 essential rules.