Quarterly planning

    Quarterly tax planning for business owners and PLLCs

    Estimated taxes are due four times a year. A short review each quarter turns those dates into a plan: how much to pay, when, and what to adjust before year end.

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    • Last reviewed October 7, 2026
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    What is quarterly tax planning for a business owner?

    Your Virtual CPA, a licensed CPA firm, helps business owners, S corporation shareholders and PLLC members review their books each quarter, project the year’s tax, and set estimated payments against the IRS due dates and the 100% or 110% prior-year safe harbor. We also check owner salary and state PTET payments. Book a free 30-minute call to set up your quarterly plan.

    Estimated tax due dates

    Individuals, including sole proprietors, partners, LLC and PLLC members and S corporation shareholders, pay estimated tax on April 15, June 15, September 15 and January 15 of the following year. If a date falls on a weekend or legal holiday, the next business day counts.

    C corporations pay installments by the 15th day of the 4th, 6th, 9th and 12th months of the tax year. For a calendar-year corporation, that is April 15, June 15, September 15 and December 15. Corporations generally must pay estimates if they expect to owe $500 or more.

    The safe harbor: 90%, 100% or 110%

    Individuals generally avoid the federal underpayment penalty if their withholding and timely estimates cover the smaller of:

    • 90% of the current year's tax, or
    • 100% of the tax shown on the prior year's return.

    If prior-year adjusted gross income was more than $150,000 ($75,000 if married filing separately), the prior-year figure rises to 110%. The prior-year method is simple and predictable. Paying based on the current year can mean lower payments in a slower year, but it needs a projection each quarter.

    S corporation owners and PTET

    S corporations must pay reasonable compensation to shareholder-employees before taking non-wage distributions. Withholding on that salary counts toward your payments for the year. The K-1 profit does not have withholding, so most owners also pay quarterly estimates or raise their W-2 withholding later in the year.

    If your business elects a state pass-through entity tax, the entity pays state tax for the owners. That changes how much each owner should pay personally. See Virginia PTET and Maryland pass-through entity tax.

    How it works with us

    Best for: owners of profitable S corporations, partnerships, LLCs and PLLCs (law, medical and consulting practices) whose income changes during the year.

    Each quarter we:

    1. Review the books through the most recent month end.
    2. Project federal and state taxable income for the year.
    3. Compare payments so far to the safe harbor and to the projection.
    4. Recommend the next federal and state estimated payments for each owner.
    5. Check S corporation salary and payroll withholding, and any PTET payments.
    6. Flag year-end decisions early, such as equipment purchases and retirement plans.

    What to send us: read-only access to QuickBooks or Xero, payroll reports for the quarter, a list of estimated payments already made, and last year's returns if we didn't prepare them. Fees are transparent and fair, quoted upfront, in writing. See also year-end tax planning.

    Federal estimated tax dates at a glance

    WhoDue dates
    Individuals (sole proprietors, partners, LLC/PLLC members, S corp shareholders)April 15, June 15, September 15, January 15 of the next year
    C corporations15th day of the 4th, 6th, 9th and 12th months of the tax year
    Weekend or holidayDue the next business day
    Individual safe harbor90% of current-year tax or 100% of prior-year tax (110% if prior-year AGI was over $150,000)

    Expert CPAs. Personal attention.

    Want a quarterly tax plan for your business? We'll review your books, project the year and tell you what to pay each quarter.

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    Frequently asked questions

    April 15, June 15 and September 15 of the tax year, and January 15 of the following year. If a due date falls on a Saturday, Sunday or legal holiday, a payment made on the next business day is on time.

    By the 15th day of the 4th, 6th, 9th and 12th months of the tax year. For a calendar-year corporation that is April 15, June 15, September 15 and December 15. Corporations generally must pay estimates if they expect to owe $500 or more.

    Individuals generally avoid the underpayment penalty if they pay at least 90% of the current year’s tax or 100% of the tax shown on the prior year’s return, whichever is smaller. If prior-year adjusted gross income was more than $150,000 ($75,000 if married filing separately), the prior-year figure is 110%.

    Often, yes. Income tax withheld from the owner’s W-2 salary counts toward the year’s payments, but S corporation profit passed through on the K-1 is not subject to withholding. Owners usually cover the gap with quarterly estimates or by adjusting withholding.

    Yes. Estimated tax covers income that is not subject to withholding, including self-employment earnings. A single-member PLLC taxed as a sole proprietorship, or a member of a PLLC taxed as a partnership, typically pays both income tax and self-employment tax through quarterly estimates.

    Yes. The IRS says you may be charged an underpayment penalty even if you are due a refund when you file, if you did not pay enough tax by each quarterly due date.