Form 1040-ES for 2026: the changes that move estimates

• Standard deduction: $32,200 joint, $24,150 head of household, $16,100 single or married filing separately.
• QBI deduction made permanent, with a $400 minimum for at least $1,000 of qualified business income.
• Charity: non-itemizers can deduct up to $1,000 ($2,000 joint) of cash gifts; itemizers deduct only gifts above 0.5% of AGI.
• Child and dependent care credit: maximum rate rises from 35% to 50% on the same $3,000 / $6,000 expense caps.
• Adoption credit or exclusion up to $17,670, with up to $5,120 refundable, below modified AGI of $305,080.
• Gambling losses deductible only up to 90% of winnings.
• Premium tax credit unavailable above 400% of the poverty line, with no cap on repaying excess advance credit.
• Senior deduction for clients born before January 2, 1962, alongside the tips, overtime and car loan interest deductions.

The IRS published a correction to the state and local tax figure in the 2026 Form 1040-ES. For 2026 the cap is $40,400, shrinking once modified AGI passes $505,000, so use the corrected amount when you build a client’s estimate.

The four 2026 payments are due April 15, June 15 and September 15, 2026, and January 15, 2027. A client whose 2025 AGI was over $150,000 ($75,000 married filing separately) needs to pay 110% of the 2025 tax to use the prior-year safe harbor.

For business owners, quarterly estimates are easier to set from a current profit and loss report than from last year’s return. HelloBooks keeps the books current through bank feeds, so you can run year-to-date profit before each due date.