What it actually costs to leave your business taxes until the last minute

If you have spoken to a few tax providers this year and decided to come back to the question in the new year, the decision itself costs nothing, but the time it uses up does, because one of the first major deadlines for the 2026 tax year falls on February 1, 2027 and each one depends on work that takes longer the later it starts.

Waiting rarely leads to a single dramatic penalty. It leads to a series of smaller costs that stack on top of one another: per-form penalties on late 1099s, a fixed penalty and monthly interest from Delaware, per-owner penalties on pass-through returns, a percentage of unpaid tax on corporate returns, and, for foreign-owned companies, a $25,000 penalty that does not scale down for small companies. The paragraphs below put a number on each one, using the IRS and Delaware figures for returns due in 2027.

Late 1099s are charged per form and per copy

Form 1099-NEC is due to the IRS and to each contractor by February 1, 2027, for each contractor who received $2,000 or more in reportable payments from your company in 2026 (most payments to corporations, and payments made by card, are excluded). The penalty is calculated per form, and the IRS treats a missing filing and a missing contractor copy as two separate failures.

For returns due in 2027, a form filed within 30 days of the deadline costs $60, one filed by August 1 costs $130, and one filed after that or not at all costs $340. A company with eight contractors that files in late March would be in the middle tier, which comes to $1,040 for the IRS filings alone. If the contractors' copies also went out in late March, they fall in the same tier and add another $1,040, for a total of $2,080 before any relief.

1099s usually go out late because the company does not have a W-9 on file for every contractor, or because its books cannot reliably separate contractor payments from other expenses until someone sits down and reconciles them.

Delaware charges a flat penalty and then keeps charging interest

A Delaware corporation that misses the March 1, 2027 deadline for its annual report and franchise tax pays a $200 penalty, plus interest of 1.5% a month on the unpaid tax. That is a nominal rate of 18% a year, and it continues until the balance is paid.

The larger risk is the size of the tax itself. If your company receives a franchise tax notice calculated under the Authorized Shares Method, the default figure can run into the tens of thousands of dollars for a company that authorized millions of shares at formation. Recalculating under the Assumed Par Value Capital Method often brings that down sharply, to a minimum of $400 plus the $50 annual report fee, though Delaware's own worked example comes to $1,600. Either way, it only helps if someone has the gross assets and issued share figures ready before the deadline. A company that pays the default notice in a hurry, or misses the date while trying to work it out, can turn a bill of a few hundred dollars into a far larger one.

A corporation that remains delinquent loses its good standing in Delaware, and a certificate of good standing is one of the first documents requested in a fundraise, a bank account review, or an acquisition.

Pass-through returns are penalized by headcount

S corporations and partnerships, including multi-member LLCs taxed as partnerships, file by March 15, 2027. These returns usually show no tax owed at the entity level, so the IRS penalizes a late filing according to the number of owners rather than the amount of tax.

For returns due in 2027, the penalty is $260 per partner or shareholder for each month or part of a month the return is late, for up to 12 months. A four-member LLC that files three months late would owe $3,120, and one that misses the year entirely would owe $12,480, on a return that showed zero tax due. If the owners' Schedule K-1s also go out late, that delays their personal returns and can bring a separate penalty.

Corporate returns cost a percentage of the unpaid tax

A C corporation that owes tax and files Form 1120 after April 15, 2027 without an extension pays a failure-to-file penalty of 5% of the unpaid tax for each month or part of a month, up to 25%. A separate failure-to-pay penalty of 0.5% a month applies to tax paid late, and in a month where both apply, the filing penalty drops to 4.5%, so the two together come to 5%.

On a $40,000 tax bill that stays unpaid, a return filed three months late carries combined filing and payment penalties of $6,000, and one filed five months late reaches $10,000. That is not a ceiling, since the payment penalty keeps running after the filing penalty maxes out. If the return is more than 60 days late, a minimum penalty applies even when the percentage would be smaller, which for returns due in 2027 is $535 or 100% of the unpaid tax, whichever is less. Interest on the unpaid tax and on the penalties runs on top of all this, at the federal short-term rate plus three percentage points, compounded daily.

Filing Form 7004 by April 15 avoids the failure-to-file penalty by moving the filing deadline to October 15, but it does not move the payment deadline. Tax that is unpaid on April 15 still attracts interest from that date, and usually the failure-to-pay penalty too, unless at least 90% was paid by April 15 and the rest is paid by the extended deadline. That is why an extension works best when it is filed by someone who has already estimated what the company owes.

Form 5472 is the one penalty that does not scale

If your US company has a foreign owner holding 25% or more and has reportable transactions with that owner or another related party, it attaches Form 5472 to its federal return. Foreign-owned single-member LLCs file it with a pro forma Form 1120, and an owner's capital contribution counts as a reportable transaction even if the company had no revenue. The penalty for missing the form, or filing a substantially incomplete one, is $25,000, and a further $25,000 applies for each 30-day period the form remains unfiled, beginning 90 days after the IRS sends a notice.

This penalty applies whether or not the company had revenue or owed tax, so for a small or pre-revenue company it can be far larger than the tax bill itself.

The costs that do not show up on a notice

Penalties are the visible part. The less visible costs come from what happens to the work when it starts late.

Catch-up bookkeeping: Books that are several months behind have to be reconstructed before any return can be prepared, and most providers bill that catch-up work as a separate project on top of the regular fee.

Peak-season pricing and availability: Tax professionals are busiest between February and April, and some publish document cutoffs, late-information fees, or limits on taking new clients during that period. A company that starts looking for a provider in March has fewer options and less room to negotiate than one that settles the question in December.

Missed savings: The choice between franchise tax calculation methods, the decision to claim an R&D credit, and the question of whether to elect a particular tax treatment all need time and complete records. Under deadline pressure, there is less time to review them properly.

The owner's time: Every week spent gathering statements, chasing contractor details, and answering a preparer's questions in February is time taken from the work the company actually exists to do.

What signing up before December 20, 2026 changes

If you sign up by December 20, 2026 and file your 2026 federal business tax return with us, your Delaware Franchise Tax filing, FBAR, Form 1099s, and Form 7004 are free for your first year, and bookkeeping is 25% off for your first six months, worth up to $1,000 in total. Our filing fees are waived, but Delaware's franchise tax and annual report fee, and any government penalties or interest, are still payable. More usefully, the work that the deadlines above depend on (preparing the year-end close, collecting W-9s, pulling year-end balances, and estimating what you owe) starts while there is still time to do it properly, and nothing is filed until you have reviewed and approved it in your dashboard.

Frequently asked questions

What is the penalty for filing business taxes late?

For C corporations that owe tax, the failure-to-file penalty is 5% of the unpaid tax per month, up to 25%. S corporations and partnerships are penalized per owner per month, which is $260 per owner for returns due in 2027, for up to 12 months, even when no tax is owed.

What is the penalty for filing a 1099 late?

The penalty is charged per form and depends on how late the form is filed. For returns due in 2027, it ranges from $60 per form within 30 days to $340 per form after August 1, with a separate penalty of the same size for not sending the contractor their copy on time.

What happens if you miss the Delaware franchise tax deadline?

Delaware charges a $200 penalty and 1.5% interest per month on the unpaid tax for corporations that miss the March 1 deadline. Companies that remain delinquent lose their good standing, which can complicate fundraising, banking, and acquisitions.

Does filing an extension avoid late penalties?

Form 7004 avoids the failure-to-file penalty by extending the filing deadline by six months. It does not extend the deadline to pay, so any tax owed is still due on the original date and attracts interest if it is paid late, plus a failure-to-pay penalty unless the 90% payment exception applies.

Can late filing penalties be removed?

For original returns due on or after January 1, 2027, the IRS applies Automatic Exemption from Penalty, which replaces first-time abatement for eligible taxpayers with a clean compliance history and needs no separate request. It covers specific penalties only, relief for reasonable cause is available in some other situations, and interest on unpaid tax generally continues to apply.