Deadlines, extensions & estimated payments

When returns are due

These are the IRS deadlines, written as the rules rather than as dates, because the exact day shifts each year — if the 15th lands on a weekend or a legal holiday, the deadline moves to the next business day.

• Individuals & sole proprietorsForm 1040 — Schedule C or F is filed with it 15th day of the 4th month after the tax year ends — April 15 for calendar-year filers
• PartnershipsForm 1065 15th day of the 3rd month after the tax year ends — March 15 for calendar-year filers
• S corporationsForm 1120-S 15th day of the 3rd month after the tax year ends — March 15 for calendar-year filers
• Corporations (not S corps)Form 1120 15th day of the 4th month after the tax year ends — April 15 for calendar-year filers. Fiscal-year filers: call us, as some year-ends follow different rules
• ExtensionsForm 4868 (individuals) · Form 7004 (businesses) Generally 6 months, though the period depends on the return and the tax year. Request it by the original due date — extra time to file is not extra time to pay
• Estimated tax paymentsForm 1040-ES and corporate equivalents Four installments across the year — see the estimated payments section below

We need your documents at least 7 days before your deadline. That is Alpha Tax's own rule, not the IRS's — it is the working time we need to prepare a return properly rather than hurriedly. Anything reaching us later than that may need an extension. If you run on a fiscal year rather than a calendar year, or you are not sure which return type you fall under, call us rather than guessing.

Drop documents at either office, or upload them through the encrypted client portal. Please do not email tax documents. For the IRS's own filing and payment dates, see the IRS when-to-file page (opens in a new tab), and for every return type and the exact dates each year, IRS Publication 509, Tax Calendars (opens in a new tab).

Extensions

An extension gives you more time to file — not more time to pay. Any tax you owe is still due on the original deadline, and the IRS charges interest on anything unpaid from that date. If you expect to owe, pay an estimate by the original deadline even if the return itself goes in later.

If your paperwork arrives inside the 7-day window, we will file an extension for you. There is a $35 service fee for this process — it keeps you compliant and can prevent far more expensive late-filing penalties.

The $35 is Alpha Tax's fee for preparing and filing the extension. It is not a payment toward your tax bill, and paying it does not by itself complete an extension — we still need your information through the portal.

1. 1
   Pay the $35 fee. On the payment page, choose “File an extension (One Time fee) — $35.00”. The menu also lists an estimated-payment item and recurring items, so check the name before you pay. You will receive a receipt from receipts@cpacharge.com containing an authorization code.
2. 2
   Send your information securely. Open the encrypted client portal and choose Guest Exchange — no account needed. Put the authorization code from that receipt, the tax year, and the returns you need extended into the Message to ALPHA TAX box, then attach any documents. Never send these by email or through a web form.
3. 3
   We file it and confirm. We will tell you once the extension has been submitted and again once the IRS accepts it.

Estimated tax payments

Estimated taxes let the IRS collect revenue as income is earned through the year. If you are self-employed, freelancing, or have substantial non-wage income, you are likely required to make periodic payments to avoid interest and penalties.

Underpaying estimated tax results in an underpayment penalty — but it is not a flat charge. It is worked out from how much you underpaid, how long it stayed unpaid, and the IRS interest rate for that period, which is reset every quarter. So there is no single figure to plan around, and exceptions and safe harbors may mean you owe nothing at all. What protects you is paying a correct amount on time. The IRS explains the calculation on its underpayment of estimated tax penalty page (opens in a new tab), and publishes the rates it uses on the quarterly interest rates page (opens in a new tab).

We calculate the correct amount and make sure the submission is completed on time. The same $35 service fee and the same two-step process applies: pay the fee — choosing “Estimated payment vouchers (One time Fee) — $35.00” at checkout — then send your information through the secure portal. As with extensions, that fee is for our work; it is not the tax payment itself.