Solo Enrolled Agents running their own practice may face the Q4 estimated-payment safe harbor under IRC §6654 and the §174 R&D capitalization rule at the same time. This post walks through a four-step planning workflow on /tax-planning and identifies points for practitioner review. It is educational content, not tax or legal advice, and does not establish Circular 230 compliance or an IRS outcome.
Q4 estimated payments — the deadline the firm-PTIN signed up for
IRC §6654 imposes a safe-harbor tier that lets the taxpayer avoid the §6654 underpayment failure-to-deposit penalty when the cumulative installment equals the lesser of (a) 90% of the current-year tax, (b) 100%/110% of the prior-year tax (the 110% applies when prior-year AGI exceeds $150k), or (c) 90% of the annualized-income-method estimate. The Q4 installment is due January 15 of the following year — meaning the solo-EA planning record has to carry a Q4 calculation the same week the §174 R&E adjustment moves onto the engagement. /tax-planning is the four-step workflow that walks the solo-EA through the income projection, the §6654 safe-harbor tier selection, the withholding reconciliation, and the journal entry that lands the installment on the right Form 1040-ES voucher. The scanner does not transmit to the IRS at any point; it surfaces each safe-harbor tier inline with the source-return drawer so the §6654 tier picking happens with the prior-year column visible, not reconstructed at year-end.
§174 R&E capitalization — the 2022 transition question on every planning record
IRC §174(a)(1) requires research and experimental expenditures paid or incurred in a trade or business to be capitalized under §174(b), with amortization over five years (domestic) or fifteen years (foreign) beginning with the midpoint of the taxable year in which the expenditures are paid or incurred. The §174(b) recovery period and the Treas. Reg. §1.174-2 capitalization mechanics were modified by the 2022 transition rule — for tax years beginning after December 31, 2021, §174 capitalization is mandatory, and amortization is over five years (fifteen for foreign). For 2026 the rule is fully in effect; the 2022–2025 transition is closed. The engagement-letter-tax-strategy clause from the prior post ("Your 2026 Engagement Letter Needs These Three Clauses") matters here because practitioners who carry §174 R&E on a client planning record need the clause specifying whether §1.263A-1 UNICAP absorbs the §174 adjustment or the §174-only treatment wins. /tax-planning surfaces that clause at the same four steps as the Q4 estimated calculation, so the §174 adjustment and the Q4 estimated installment travel the same engagement file.
What the "owner-review" workflow looks like in practice
Circular 230 and §7216 may be relevant to a practitioner’s engagement, but this product description does not determine those obligations or certify compliance. The four-step planning workflow on /tax-planning presents an income projection, a §6654 scenario, a §174 scenario, and a reviewer decision boundary. A cataloged item may include the citation stored with its entry; the practitioner must verify the source, facts, tax year, and filing treatment. Any audit record, retention period, or exam sufficiency remains subject to the deployed configuration and qualified review.
A review-time scenario, not a forecast
A firm may use a four-step Q4 estimated-payment and §174 review to organize its working papers. Any time or client-volume example is illustrative only; Taxerity.AI does not guarantee recovered time, savings, accuracy, or a particular exam result.
§174 + Q4 estimated interplay: an example record
A single planning record on a Schedule C can be used to organize several review topics, including a Q4 estimated-payment scenario, a §174 R&E capitalization scenario, and a separate §41 research-credit question. The practitioner must verify each source, fact pattern, tax year, consent requirement, and filing treatment; the workflow does not determine the answer or certify the resulting record.
Closing — /book-demo is a single click away
The four-step workflow on /tax-planning is available for practitioners who want to inspect the product’s review boundaries. It does not replace professional judgment, tax advice, or the firm’s own engagement and recordkeeping decisions. Book a 15-minute walkthrough → /book-demo to review the workflow with the Taxerity.AI team.