The business calendar

Know what is coming, prepare the work and verify the result

Black Lentil Editorial · September 20, 2026

U.S. federal deadlines with state and local research reminders. The online calendar and optional download cover September 21, 2026–January 31, 2027. It combines selected federal deadlines with a suggested operating rhythm. It is a planning aid, not a complete determination of every business's obligations.

A useful business calendar connects a date to the work behind it. Each entry should answer: does this apply to this business, who owns it, what must be ready, what happens on the date, and how will we know it happened?

The companion tax masterclass explains the underlying concepts. This calendar gives that work a place in the week and month. It also covers cash, customers, costs, capacity and renewals so tax preparation does not become the only reason to review the business.

Choose the entries that apply

Federal deadline means a selected official date, subject to the stated taxpayer and period. The filing and payment years appear separately where needed. Confirm any disaster relief, special rule or fiscal-year difference before relying on a date.

Suggested review means a working appointment proposed by Black Lentil. Move it to fit the business. Monday reviews, first-Monday closes and the other review dates below are not legal deadlines.

Your date means an obligation determined by a contract, provider, business location or agency notice. The calendar gives you a way to record it, but does not invent it.

Start by confirming federal tax classification, year-end, employees, locations and sales activity. A sole proprietor and an S corporation owner can both need personal estimated payments, but their business returns and owner-pay processes differ. Use the obligation map from Lesson 1 before removing or adopting a tax event.

The next months at a glance

The federal entries are explained below, including the people and businesses to whom they apply. Review dates are recommendations that can be moved.

The weekly cash review continues every Monday through January 25. Suggested dates can fall on holidays or inconvenient operating days; reschedule those reviews. Rescheduling an official obligation requires an applicable rule, not a preference.

Selected federal deadlines, with the work attached

October 15, 2026 — extended individual return

Applies to: individuals with a valid ordinary six-month extension for their 2025 federal return. This is not the first due date for paying 2025 tax. Prepare: reconcile the books, collect missing documents, review the return and resolve questions with the preparer. Verify: retain the accepted filing and independently reconcile any payment. IRS: individual filing extensions

October 15, 2026 — extended C corporation return

Applies to: calendar-year corporations with a valid six-month extension for the 2025 Form 1120. Prepare: the final entity return, reconciliations and authorization. Verify: acceptance and any payment separately. This entry is not an S corporation deadline. IRS: fourth-quarter calendar

November 2, 2026 — ordinary Q3 Form 941 filing date

Applies to: employers required to file Form 941 for July–September 2026. Prepare: reconcile wages, withholding, employer taxes and deposits. Verify: an accepted return and supported deposit balances. Qualifying employers that timely deposited all required taxes have a later filing date, November 10; confirm eligibility before using it. Filing dates do not replace deposit schedules. IRS: Form 941 timing and conditions, IRS: fourth-quarter calendar

November 2, 2026 — FUTA deposit where required

Applies to: employers whose accumulated undeposited FUTA through September exceeds $500. Prepare: the FUTA calculation, including carryover. Verify: payment to the correct tax period. A business below the threshold must still track the liability and applicable carryforward rule. IRS: employment tax due dates

December 15, 2026 — corporation estimated-tax installment

Applies to: calendar-year corporations required to make this 2026 estimated payment. Prepare: a reviewed calculation, credited prior payments and sufficient cash. Verify: the installment reached the intended taxpayer and year. This is not the fourth individual estimated-payment date. IRS: fourth-quarter calendar

January 15, 2027 — individual estimated payment for 2026

Applies to: calendar-year individuals required to make the fourth 2026 installment, including applicable sole proprietors and pass-through owners. Prepare: the updated calculation and payment history. Verify: payment for tax year 2026, although the calendar date is in 2027. Special rules apply, including the early-filing alternative described in the form instructions; do not omit payment without confirming qualification. IRS: 2026 Form 1040-ES

Why payroll does not have one universal monthly date

Payroll deposits can follow monthly or semiweekly schedules, and a $100,000 accumulated liability can trigger next-business-day payment. The appropriate schedule depends on the rules and business history, not on how often this calendar suggests reviewing cash. Confirm the schedule with your payroll provider and place the actual deadlines in your own calendar. IRS: employment tax due dates

The starter therefore includes a reminder to confirm payroll dates, not a guessed set of payroll deposits. Also identify annual wage reporting, unemployment, retirement-plan and other forms relevant to your business. This selected calendar does not contain them all. Start planning the next filing season during the January 11 handoff rather than assuming the final event here is your final obligation.

Every week — cash and commitments

Suggested date: Monday, beginning September 21. Owner: the owner or named finance lead. A suggested starting time budget is 20–30 minutes; adjust it to the work.

Start with cash actually available. Update expected receipts using current evidence about when customers will pay. Add required payments for wages, suppliers, rent, debt and taxes. Identify the lowest forecast balance and whether any payment lacks funding. Use the existing 13-week cash workbook if that horizon suits the business.

Then review outstanding commitments. A purchase approval, customer promise or unanswered invoice can create work before it creates a bank transaction. Give any shortfall or delay a named person and an action date. If you are working alone, write the next action explicitly so “follow up” does not replace a decision.

Keep as evidence: a dated forecast and an exception list with amount, responsible person, next action and follow-up date. Finished means: differences from the previous forecast are explained and every material funding gap has an assigned response. It does not mean the cash problem has vanished.

Example: An expected $4,000 customer payment moved from this Friday to next month. Update the receipt date and check the effect on payroll and other commitments. The calendar review is useful only if the changed assumption changes the plan.

Every month — close the books and review the next obligations

Suggested date: the first Monday after month-end. If records will not be available then, choose a realistic target and retain a visible list of pending records. Owner: bookkeeper or owner; preparer reviews disputed tax treatment.

Reconcile bank and card accounts to the books. Trace processor deposits to sales, refunds, fees and settlement timing. Examine receivables, payables, payroll liabilities and loan movements. Attach missing support or assign its recovery. Compare profit and cash without assuming they should match.

Use the reconciled result to revisit tax estimates and the cash reserved for them. Review your agency notices and next 60 days of verified state/local deadlines, registrations, permits and renewals. A calendar event labelled “check state taxes” is only a research prompt; replace it with the actual agency obligation once confirmed.

Keep as evidence: reconciliations, a current profit-and-loss report, balance-sheet review, payment history and a dated open-item list. Finished means: the books' status is clear and the next decisions have dependable inputs. If an account is unreconciled, say so; do not label an incomplete month final merely because the review date passed.

This connects to Lessons 2, 3, 5 and 7 of the tax masterclass.

Every month — customers, prices and delivery

Suggested date: the last Wednesday. Owner: the person who can change sales follow-up, pricing or delivery commitments.

Review inquiries, response times, quotes, sales and repeat business using records you actually hold. Separate missing measurement from a genuine zero. Look at where people stop: before contact, after asking, after receiving a quote or after the first purchase. Choose a specific problem to investigate rather than assuming all weak sales are a traffic problem.

Compare prices with current costs and capacity. A busy calendar can coexist with weak contribution or slow collection. Identify overdue customer work, recurring rework and promises that no one owns. Pick one change, name its owner and set the evidence and date for reviewing the result.

Keep as evidence: the numbers reviewed, their source and period, the decision and the next check. Finished means: there is an action someone can perform and a way to tell whether it helped. A discussion with no recorded decision is still unfinished.

Example: There were 18 inquiries, 12 replies and four quotes. Before buying more advertising, investigate the six unanswered inquiries and why eight replies did not progress. These fictional numbers illustrate a question to examine; they do not establish a universal conversion target.

Quarterly and year-end reviews

October 12 — choose Q4 commitments

Review cash, margins, customer demand and delivery capacity together. Decide which commitments fit the people and money available. Examine software and vendor renewals over the next 90 days, including notice periods. Assign one person to each material decision and record what evidence would justify changing it. Retain a short set of priorities, the tradeoffs and the next review date. This is a suggested planning session, not a filing deadline.

November 9 — make year-end decisions while choices remain

Bring the current books, expected year-end result, household changes where relevant, asset plans and employee changes to the tax-preparer discussion. Ask which decisions have establishment, election, service-date or funding requirements. Record the exact rule and date for the decision that applies; do not assume every deduction or retirement contribution has a December 31 deadline.

Compare cash cost with confirmed tax effects before committing to a purchase. Retain the calculation, assumptions and decision. The meeting is finished when unresolved decisions have an owner and a date early enough to act—not merely when a call occurred.

December 14 — prepare the year-end evidence

Check missing invoices, expense support, asset records, payroll reports and contractor information. Plan any inventory count needed for the business's accounting method. Decide who will document transactions around year-end so timing is supportable. Review upcoming renewals and January commitments. Retain an evidence checklist with missing items assigned; this preparation date is not the legal deadline for those items.

January 11 — hand off the records and confirm the next filing calendar

Give the preparer a reconciled packet, payment history and a clear question list through an agreed private channel. Confirm who handles each return and information report, when records are needed and how acceptance will be verified. Add the verified 2027 filing deadlines relevant to the business; this starter stops in January and does not silently roll its dates forward.

Add your state, local and contract dates

Use official agency instructions, notices and signed agreements. Start with the state revenue agency, labor/unemployment agency, business registry and relevant city/county offices. Location and structure affect obligations; operating or selling across borders may require additional analysis. SBA: managing business tax obligations

For each, record the business/entity, period, source, date last checked, preparer, approver, person performing the action and evidence required. Keep unknown dates visibly unresolved. Review these on setup and whenever location, staffing, sales activity, contracts or ownership changes.

Put preparation and verification around the deadline

For a substantial obligation, work backward from the actual due date. A possible starting pattern is to collect records 30 days before, resolve questions 14 days before and authorize submission/payment early enough for the chosen method. These are planning suggestions, not statutory cutoffs. Confirm banking/provider cutoff times separately; an all-day calendar entry does not show them.

After the action, verify filing acceptance and payment separately. Keep “prepared,” “authorized,” “submitted,” “accepted” and “payment verified” distinguishable in your private work record. An imported event is a reminder, not proof of completion.

Use the download

The `.ics` file contains full event descriptions and source links for the federal entries. It contains no invitees, email actions or built-in alarms. All events are all-day markers that leave your time available. Review applicability and set reminders in your calendar app after import; the file cannot know your taxpayer classification or notification preferences.

Import into a separate calendar first so you can review and remove entries without mixing them with personal appointments. An import is a static copy, not an updating subscription. Duplicate imports may create duplicates depending on the app. Changes to agency rules will not automatically update an imported file.

No events have been imported into your account. No personal information is included. The online list and calendar download use the same event records. Filter the list by month, type or topic without changing the underlying dates.

Review and maintenance

Sources checked September 20, 2026. The federal dates were checked against the linked IRS guidance; suggested reviews are Black Lentil planning choices. This calendar has not received independent tax-professional review and is not a complete federal, state or local compliance schedule. Check current instructions, disaster relief and your business’s circumstances before relying on an event. This edition ends January 31, 2027; later obligations are not included. A downloaded copy will not update automatically.