Business Tax Preparation & Compliance Services
Expert preparation for S-Corps, partnerships, and LLCs from CPAs who specialize in pass-through entities. We don’t just file returns. We look for opportunities.
Key Takeaways
- Expert tax preparation for S-Corps (Form 1120S), partnerships (Form 1065), and LLCs
- We analyze every return for missed deductions, basis errors, and planning opportunities
- Average client saves $47,000/year through optimization strategies
- Partnership and S-Corp specialists (80% of our practice)
- Upfront estimates before we start work. No surprises.
Business tax preparation services include filing the correct tax forms for your entity type: Form 1120S for S-Corporations, Form 1065 for partnerships, Form 1120 for C-Corporations, and Schedule C for single-member LLCs. Beyond filing, quality preparation includes basis tracking, deduction optimization, K-1 preparation for shareholders/partners, and identifying errors from prior years. Tax compliance means meeting all deadlines and maintaining documentation that survives IRS scrutiny.
Tax Preparation That Goes Beyond Filing
Standard tax preparation focuses on filing accurately and on time. That’s the baseline. We go further: analyzing prior returns for optimization opportunities, verifying basis calculations, and identifying deductions that may have been overlooked.
Pass-through entities like S-Corps and partnerships require specialized knowledge. QBI deductions depend on spouse income and W-2 wages. Basis tracking affects gain/loss on distributions. Reasonable salary has IRS-specific guidelines. These details matter, and they’re easy to miss without focused expertise.
Before we prepare your current year, we analyze your prior returns looking for opportunities. Many business owners have $5,000-$20,000 in identifiable improvements.
Why Specialization Matters
We recently helped a partnership client recover $18,400 through amended returns after identifying a missed Section 199A deduction. The calculation required spouse income data that wasn’t originally collected. This is the kind of detail that requires deep pass-through experience.
Compliance isn’t just filing on time. It’s filing correctly. It’s maintaining basis tracking that would survive an audit. It’s ensuring your K-1s match your operating agreement. It’s documenting your reasonable salary analysis before the IRS asks for it.
Wondering if there are opportunities in your current returns? Schedule a consultation and we’ll take a look.
Tax Preparation Services by Entity Type
S-Corporation Tax Preparation
Form 1120S preparation with shareholder K-1s. We handle the complexity so you don’t have to.
- Reasonable salary documentation and analysis
- QBI deduction optimization (Section 199A)
- Shareholder basis tracking
- Officer compensation planning
- K-1 delivery to shareholders on time
Partnership Tax Preparation
Form 1065 preparation with partner K-1s that survive IRS scrutiny.
- Proper basis tracking for all partners
- Special allocations per operating agreement
- Multi-state allocation and apportionment
- Partner capital account maintenance
- K-1s that match your partnership agreement
LLC Tax Preparation
Single-member or multi-member, we handle all LLC tax structures.
- Schedule C for single-member LLCs
- Form 1065 for multi-member LLCs
- S-Corp election analysis (Form 2553)
- Self-employment tax optimization
- Entity conversion guidance
Multi-Entity Coordination
Multiple companies need coordinated strategy, not separate CPAs.
- Holding company + operating company structures
- Intercompany transactions and allocations
- Consolidated planning across entities
- Real estate + operating business coordination
- Single point of contact for all filings
What Is Tax Compliance? (And Why It Matters)
Tax compliance means meeting all tax filing obligations accurately and on time. For businesses, this includes:
- Filing the correct forms (1120-S for S-Corps, 1065 for partnerships, 1120 for C-Corps)
- Paying estimated taxes quarterly
- Issuing K-1s to shareholders/partners on time
- Maintaining documentation that survives an IRS audit
- Meeting all federal, state, and local filing requirements
Compliance vs. Planning
Compliance is table stakes. It’s doing your taxes right. Tax planning is the value-add. It’s paying less next year. Good compliance protects you in an audit. Good planning reduces what you owe. You need both. We provide both.
The penalties for non-compliance are significant. S-Corps and partnerships face $235 per shareholder/partner per month for late filing, up to 12 months. A 4-partner partnership filed 3 months late? That’s $2,820 in penalties before any tax is even calculated.
Beyond penalties, poor compliance creates problems years later. Incorrect basis tracking means wrong gain/loss calculations when you sell. Missing documentation means denied deductions in an audit. Proper record-keeping from day one prevents these issues.
Business Tax Filing Deadlines 2026
For 2025 tax year returns filed in 2026:
| Filing Type | Form | Due Date | Extended Due Date |
|---|---|---|---|
| S-Corporations | Form 1120S | March 17, 2026 | September 15, 2026 |
| Partnerships | Form 1065 | March 17, 2026 | September 15, 2026 |
| C-Corporations | Form 1120 | April 15, 2026 | October 15, 2026 |
| Single-Member LLCs | Schedule C (with 1040) | April 15, 2026 | October 15, 2026 |
| Texas Franchise Tax | Form 05-158 | May 15, 2026 | November 16, 2026 |
Estimated Tax Payments (2026)
- Q1: April 15, 2026
- Q2: June 16, 2026
- Q3: September 15, 2026
- Q4: January 15, 2027
Extension Doesn’t Mean Extension to Pay
Filing an extension (Form 7004) extends your filing deadline by 6 months. It does NOT extend your payment deadline. Taxes are still due by the original deadline. We coordinate extension filings with payment estimates to avoid underpayment penalties.
Common Tax Optimization Opportunities
Pass-through entity taxation is complex. Here are the areas where we most frequently find savings for clients:
QBI Deduction Optimization
Section 199A calculations require spouse income, W-2 wages, and UBIA data. Often overlooked in complex situations.
$8,000-$25,000Basis Tracking
Partnership and S-Corp basis must be tracked from formation. Critical for distributions and eventual sale.
$10,000-$50,000+S-Corp Salary Optimization
Reasonable compensation must balance IRS requirements with payroll tax efficiency.
$5,000-$15,000Depreciation Strategy
Section 179, bonus depreciation, and cost segregation can accelerate deductions significantly.
$3,000-$20,000Multi-State Allocation
Businesses operating in multiple states need proper apportionment to avoid over-taxation.
$2,000-$10,000Retirement Contributions
Solo 401(k) and SEP-IRA limits are generous but require proper setup and timing.
$5,000-$15,000These opportunities require specialized knowledge of pass-through taxation. Our focus on S-Corps and partnerships means we know where to look.
Schedule a consultation to discuss your situation.
How Much Does Business Tax Preparation Cost?
Tax preparation fees depend on entity type, complexity, and state filing requirements. Here’s what to expect:
| Entity Type | Typical Range | Factors That Increase Cost |
|---|---|---|
| S-Corporation (Form 1120S) | $1,200-$3,500 | Multiple shareholders, states, complex transactions |
| Partnership (Form 1065) | $1,000-$5,000 | Partner count, special allocations, real estate |
| C-Corporation (Form 1120) | $1,500-$4,000 | Revenue size, international, M&A activity |
| Single-Member LLC (Schedule C) | $300-$800 | Vehicle deductions, home office, inventory |
| Multi-Entity Coordination | $2,500-$8,000+ | Entity count, intercompany transactions |
We provide upfront estimates before starting. No hourly billing surprises. If scope changes during the engagement, we discuss it first.
The Real Cost of “Cheap” Preparation
A $500 tax return that misses $8,000 in deductions costs you more than a $1,500 return that finds them all. We’ve had clients switch from $800 preparers and save $15,000 in year one. The preparation fee isn’t your cost. Your tax bill is.
See our pricing page for detailed information.
CPA vs. Tax Preparer: When You Need a CPA
Not every business needs a CPA. Here’s when you do:
You Need a CPA If:
- You have an S-Corporation or partnership (not sole prop)
- You operate in multiple states
- You have international operations or owners
- You have complex allocations or distributions
- You want proactive tax planning, not just filing
- You might face an IRS audit (CPAs can represent you)
A Tax Preparer May Be Fine If:
- Simple Schedule C sole proprietorship
- Single state, straightforward income
- No complex deductions or business assets
- You just need accurate filing, no planning
CPAs have additional education requirements, pass a rigorous four-part exam, and maintain continuing education. More importantly for business owners, CPAs can represent you before the IRS and are held to professional standards by state boards.
For S-Corps and partnerships? The complexity of pass-through taxation, basis tracking, reasonable salary, and QBI calculations requires CPA expertise. Using a non-CPA preparer for these entities is risky.
Our Tax Preparation Process
Step 1: Prior Return Analysis
We analyze your last 2-3 years looking for errors and missed opportunities. Most clients have $5K-$20K in identifiable improvements.
Step 2: Document Collection
Secure upload through our client portal. Entity-specific checklist provided. No back-and-forth for missing items.
Step 3: Return Preparation
Draft return with all applicable deductions, proper basis tracking, and accurate allocations. We identify issues before they’re problems.
Step 4: CPA Review
Every return receives CPA review. We verify calculations, check prior year consistency, and ensure current law compliance.
Step 5: Return Explanation
We explain your return. You understand your tax position, what drove your liability, and planning opportunities for next year.
Step 6: E-File & K-1 Delivery
E-file all returns. K-1s delivered promptly to partners/shareholders. Payment coordination. Never scrambling for deadlines.
Frequently Asked Questions
What is tax compliance?
Tax compliance means meeting all tax filing obligations accurately and on time. For businesses, this includes filing the correct forms (1120-S for S-Corps, 1065 for partnerships), paying estimated taxes quarterly, and maintaining documentation that would survive an IRS audit. Compliance is the foundation. Without accurate compliance, tax planning strategies can fail.
How much does business tax preparation cost?
Business tax preparation costs vary by entity type and complexity. S-Corp returns (Form 1120S) typically range $1,200-$3,500. Partnership returns (Form 1065) start at $1,000 and increase with partner count. Simple single-member LLCs filing on Schedule C range $300-$800. We provide upfront estimates before starting work. See our pricing page for details.
What’s the difference between tax preparation and tax planning?
Tax preparation is recording what happened and filing returns. Looking backward. Tax planning is modeling scenarios and making decisions to reduce future taxes. Looking forward. Most CPAs only do preparation. If your CPA only calls you in March, you’re only getting preparation. Learn about our tax planning services.
When are business tax returns due in 2026?
For 2025 tax year: S-Corps (Form 1120S) and Partnerships (Form 1065) are due March 17, 2026. C-Corps (Form 1120) are due April 15, 2026. Extensions give 6 additional months but don’t extend payment deadlines. Texas franchise tax is due May 15, 2026.
What’s the penalty for filing business taxes late?
S-Corps and Partnerships face $235 per shareholder/partner per month, up to 12 months (maximum $2,820 per owner). A 4-partner partnership filed 3 months late faces $2,820 in penalties. Late payment penalty is 0.5% per month up to 25%, plus interest. Extensions avoid late filing penalties but not late payment penalties.
Do I need a CPA or can I use a tax preparer?
For simple Schedule C sole proprietorships, a qualified tax preparer may suffice. For S-Corps, partnerships, or any complex situation, you need a CPA. The complexity of pass-through taxation requires CPA expertise. CPAs also can represent you before the IRS and are held to professional standards.
What documents do I need for business tax preparation?
Required documents include: prior year tax returns, year-end financial statements, bank and credit card statements, payroll reports, 1099s issued and received, asset purchase documentation, loan statements, vehicle mileage logs, and home office measurements. S-Corps need officer compensation records. Partnerships need partner capital account records.
What optimization opportunities exist in business tax returns?
Common opportunities include: proper basis tracking, QBI deduction optimization ($8,000-$15,000 potential), S-Corp reasonable salary analysis, depreciation strategy (Section 179, bonus depreciation), multi-state apportionment review, and retirement contribution maximization. These areas require specialized pass-through expertise.
How do I file taxes for an LLC for the first time?
Single-member LLCs file on Schedule C with your personal Form 1040. Multi-member LLCs default to partnership taxation (Form 1065). You can elect S-Corp taxation by filing Form 2553. First-year filers should establish basis tracking immediately. This prevents problems when you eventually sell or dissolve.
Does SDO CPA handle multi-state tax returns?
Yes. About 40% of our clients operate in multiple states. We handle state allocation, nexus analysis, composite returns, and multi-state compliance. Common scenarios include Texas businesses with California customers, partnerships with partners in different states, and companies with remote employees creating nexus.
Tax Preparation Guides & Tools
Complete guide to S-Corp taxation, elections, and optimization
Partnership tax rules, basis tracking, and distributions
Compare S-Corps, C-Corps, partnerships, and sole props
Estimate your S-Corp tax savings vs. sole proprietorship
Calculate your Section 199A deduction
Extension filing guide for business returns
Transparent pricing for tax preparation services
Related Services
Ready to Work With Pass-Through Specialists?
S-Corps and partnerships are complex. Work with CPAs who focus on them every day. Get proactive tax optimization, not just annual filing.
Schedule a ConsultationOr call us directly: (972) 296-0981
SDO CPA LLC is a licensed CPA firm in the state of Texas, regulated by the Texas State Board of Public Accountancy (22 TAC §501.82). Services described are subject to engagement terms. Results vary based on individual circumstances. Average client savings based on documented tax optimization strategies implemented during first engagement year. This communication does not guarantee outcomes or imply ability to influence any government agency. Member of the American Institute of Certified Public Accountants (AICPA).