SterlynFinancial Partners Book a free consultation

Business tax returns, prepared and filed by licensed CPAs.

Federal and state returns for C-Corps, S-Corps, partnerships and LLCs, including foreign-owned LLCs. We work from clean books, so the numbers on your return hold up.

Returns & deadlines

Which return your business files, and when.

Federal due dates for the 2026 tax year, for businesses on a calendar year.

Business typeFederal returnDueWith extension
S-CorporationIncluding LLCs that elected S-Corp statusForm 1120-SMar 15, 2027Sep 15, 2027
PartnershipIncluding multi-member LLCsForm 1065Mar 15, 2027Sep 15, 2027
C-CorporationForm 1120Apr 15, 2027Oct 15, 2027
Foreign-owned single-member LLCForm 5472 + pro forma 1120Apr 15, 2027Oct 15, 2027
U.S.-owned single-member LLCReported on the owner's personal returnSchedule C (Form 1040)Apr 15, 2027Oct 15, 2027

An extension (Form 7004 for businesses) gives more time to file, not more time to pay. Tax owed is still due by the original date. State deadlines vary and are handled as part of every engagement.

What's included

More than the return itself.

Every business tax engagement covers the federal return plus the filings that go with it.

  • ✓
    Federal return

    Form 1120, 1120-S or 1065, prepared from your year-end books.

  • ✓
    State returns

    Income and franchise tax returns for the states you operate in.

  • ✓
    Owner K-1s

    Schedule K-1s for each partner or shareholder, sent on time for their personal returns.

  • ✓
    Extensions when needed

    Form 7004 filed before the deadline if your books are not ready.

  • ✓
    1099 filing

    1099-NEC and 1099-MISC for contractors and vendors you paid during the year.

  • ✓
    Estimated tax plan

    Next year's quarterly estimates worked out, so there are no surprises.

  • ✓
    S-Corp election advice

    Whether an S-Corp election (Form 2553) would save you tax, and a reasonable salary if it does.

  • ✓
    IRS notice help

    We read and answer IRS or state notices about the returns we prepared.

How filing works

From documents to accepted return.

You approve every return before it goes to the IRS.

Step 1

Kickoff

A short call and a document checklist for your business.

Step 2

Books review

We check that the year is closed and reconciled, and fix what is not.

Step 3

Prepare

Federal and state returns drafted, with K-1s for each owner.

Step 4

CPA review

A licensed CPA reviews the return line by line.

Step 5

Your approval

We walk you through the return. You sign the e-file authorization.

Step 6

E-file

Filed with the IRS and states. You get accepted copies for your records.

What to send us

Your document checklist.

If we already keep your books, we have most of this.

  • Last year's federal and state returns
  • Access to your books, or year-end financial statements
  • Bank and credit card statements for the full year
  • Payroll reports (Forms 941, 940, W-2 summary)
  • 1099 forms your business received
  • Purchases or sales of equipment, vehicles or property
  • Loan statements showing year-end balances and interest
  • Ownership changes and owner contributions or draws
  • States where you have employees, property or sales
  • IRS or state notices received during the year

Books not ready for tax season?

We clean up and close the year first, then prepare the return. If you are behind on past years, we catch up the books and file any outstanding returns.

Talk to us about cleanup

FAQ

Business tax questions.

My business had no income this year. Do I still need to file?

Usually yes. Corporations, S-Corps and partnerships generally must file a return every year they exist, even with no activity. Foreign-owned single-member LLCs must file Form 5472, and the IRS penalty for missing it starts at $25,000.

I own a U.S. LLC but live outside the U.S. Can you help?

Yes. We prepare Form 5472 with the pro forma Form 1120 for foreign-owned single-member LLCs, and partnership returns for LLCs with more than one owner.

Should my LLC elect to be taxed as an S-Corp?

It can lower self-employment tax once profit is high enough to support a reasonable salary for the owner. We run the numbers for your business before recommending it.

Does an extension give me more time to pay?

No. An extension gives you more time to file only. We estimate what you owe and help you pay it by the original due date to avoid penalties and interest.

Can you file returns for past years I missed?

Yes. We rebuild the books for each missing year and file the outstanding federal and state returns.

Contact

Book a free consultation.

Tell us a little about your business and we will reply within one business day.

Phone & WhatsApp+1 (617) 214-4889
Emailinfo@sterlynfinancialpartners.com
WhatsApp us