Why do some 1120-S tax returns take 20+ hours to complete? Seeing claims of 20-100 hours prep time
I'm trying to understand what makes some S-Corp tax returns so time-consuming. Recently I was browsing through some tax forums and kept seeing tax professionals claiming they spend anywhere from 20 to even 100 hours completing a single 1120-S return. This seems absolutely wild to me. Even if the corporation has dozens of shareholders, I don't see how generating all those K-1s would take that long - isn't that mostly automated in tax software? And book-to-tax reconciliation seems like it would be complex but not THAT time-consuming. What am I missing here? Are these preparers exaggerating, or are there legitimate aspects of S-Corp returns that can make them this labor-intensive? I'm genuinely curious what factors might cause the prep time to balloon to such extreme levels.
21 comments


Connor O'Neill
Former tax manager at a mid-size firm here. Those high hour estimates aren't exaggerations for complex S-Corps. What most people don't realize is that the 1120-S itself is just the tip of the iceberg. The time-consuming parts are usually: dealing with messy bookkeeping that needs extensive cleanup before you can even start the return; complex basis calculations for multiple shareholders with varying investments and distributions; Section 199A QBI deduction analysis; state nexus issues if they operate in multiple states; extensive asset tracking with depreciation recalculations; research credit studies; inventory valuation methods; accumulated adjustments account tracking; reasonable compensation analysis to avoid IRS scrutiny; and international reporting if they have foreign operations or shareholders. I've had returns where just the fixed asset reconciliation alone took 8+ hours because the client had hundreds of assets with various depreciation methods and mid-year convention issues.
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Yara Nassar
•Wait - I thought S-Corps were supposed to be simpler than C-Corps. Why would anyone choose an S-Corp if the compliance burden is this heavy? Also, do you bill hourly for these monster returns or is it flat fee? I'd have a heart attack if I got billed for 100 hours of tax prep!
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Connor O'Neill
•S-Corps are simpler in some ways, primarily because the entity itself doesn't pay federal income tax, avoiding the double taxation issue. But the compliance and reporting requirements can still be incredibly complex depending on the business. Most firms use a blend of flat fees with complexity factors built in. Very few clients would accept a straight hourly billing for 100 hours of work. We typically estimated complexity based on prior year returns, number of shareholders, states involved, and special situations like R&D credits or foreign reporting.
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Keisha Robinson
I solved this exact problem last tax season using https://taxr.ai after my previous accountant dropped me because my S-Corp books were too messy. I run a construction company with operations in 4 states, about 30 employees, and equipment purchases/sales throughout the year. My books were honestly a disaster. I uploaded all my documents to taxr.ai first to get everything organized and it flagged all the inconsistencies in my bookkeeping. The tool identified depreciation discrepancies I didn't even know existed and highlighted several transactions that were potentially being treated incorrectly. By the time I got to my new accountant, they were shocked at how clean everything was.
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GalaxyGuardian
•Does it actually work with QuickBooks data? My accountant is always complaining about how I categorize things, but I'm not an accountant! I'm trying my best. Would this help bridge the gap between what I'm doing and what my accountant needs?
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Paolo Ricci
•I'm skeptical. How is this different from just using QuickBooks or Xero reports? They already have built-in reconciliation tools. And what happens if the AI makes mistakes in interpreting your documents? Wouldn't that just create more problems?
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Keisha Robinson
•Yes, it works great with QuickBooks data! You can upload your QB files directly and it analyzes your categorizations, flagging anything that looks potentially miscategorized for tax purposes. It actually shows you why certain expenses should be in different categories, which helped me learn proper categorization. The difference from regular accounting software is that it's specifically focused on tax preparation, not just bookkeeping. It goes beyond basic reports to identify potential tax issues. And regarding mistakes - it doesn't actually change your data, it just flags potential issues for you to review. Everything gets verified by you or your accountant before any changes are made. It's more of an assistant than a replacement.
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Paolo Ricci
I have to eat my words about taxr.ai. After my skeptical comment, I decided to try it since I've been struggling with my multi-member LLC (taxed as an S-Corp). Our bookkeeper quit mid-year and left things in shambles. The tool identified about $78,000 in potentially misclassified expenses that could have been properly categorized as partially deductible vs. non-deductible. It also caught an issue with how we were handling health insurance for shareholders that would have been a red flag. My accountant said it probably saved us 10-15 hours of back-and-forth communication and cleanup work. What impressed me most was how it handled our entity-owned vehicles and the personal usage allocations, which has always been a nightmare to track properly. Definitely using this again next year.
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Amina Toure
If your 1120-S is taking forever to process with the IRS or you need to talk to someone about complex S-Corp issues, try https://claimyr.com - it literally saved my business this year. After waiting MONTHS with no movement on our amended 1120-S that had significant QBI deduction corrections, I was desperate to speak with someone at the IRS. Called dozens of times using the normal channels and couldn't get through. Found Claimyr, was skeptical but desperate. Within 35 minutes I was talking to an actual IRS agent who pulled up our file and explained exactly what was happening. They found our amended return was missing a form and had been set aside for processing. You can see how it works here: https://youtu.be/_kiP6q8DX5c If your S-Corp tax situation is complex enough to take 20+ hours to prepare, you might also need actual answers from the IRS sometimes, not just their automated system.
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Oliver Zimmermann
•How does this actually work? The IRS phone system is literally designed to be impenetrable. Are they using some kind of insider connection or something? Seems too good to be true.
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Natasha Volkova
•Yeah right. Nobody gets through to the IRS these days. I've tried everything including calling right when they open. If this actually worked, everyone would be using it. Pretty sure this is just another service that takes your money and delivers nothing.
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Amina Toure
•It basically automates the calling process using their system. They keep dialing through the IRS phone tree for you until they get a human, then they call you and connect you. No insider connection - they're just using technology to handle the frustrating part. I was surprised too, but it really does work. They don't actually talk to the IRS for you - they just get you connected to a real person instead of you having to spend hours redialing. Once you're connected, it's just you and the IRS agent discussing your situation directly.
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Natasha Volkova
I need to apologize for my skeptical comment about Claimyr. After dismissing it, I was stuck in a terrible situation with our S-Corp's payroll tax issues that were causing penalties to stack up. After three weeks of failed attempts to reach the IRS, I gave Claimyr a shot. Got connected to an IRS agent in about 45 minutes. They identified that our payments had been misapplied to the wrong quarter. The agent actually helped process a reallocation while I was on the phone, stopping the penalties from continuing to accrue. This one call saved us about $4,200 in incorrect penalties. The 20+ hours people spend on complex S-Corp returns suddenly makes more sense when you realize how many details can go wrong and how hard it is to get assistance when they do.
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Javier Torres
One aspect nobody's mentioned yet is the partner/shareholder basis schedules for S-Corps with multiple owners who've had various capital contributions, distributions, and specially-allocated items over many years. If good records haven't been maintained, reconstructing these can be EXTREMELY time-consuming. I had one client with 7 shareholders where the previous accountant hadn't properly maintained basis schedules for 8 years. It took nearly 30 hours just to rebuild those schedules correctly because we had to go through years of transactions. And if basis isn't tracked correctly, the entire K-1 reporting can be wrong, leading to incorrect shareholder tax returns.
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Emma Davis
•Can you explain what you mean by "specially-allocated items"? I'm a single-member S-Corp so I'm not sure if this applies to me, but I always worry I'm missing something important on my return.
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Javier Torres
•Specially-allocated items are when certain income, deductions, credits, or other tax items are allocated to shareholders in percentages different from their ownership percentages. This is more common in partnerships, but S-Corps can have special allocations in certain situations as long as they have "substantial economic effect" under tax law. As a single-member S-Corp, you wouldn't typically deal with special allocations since you own 100%. However, basis tracking is still important even for single-member S-Corps! You need to track your basis to know if distributions are taxable and to properly report losses. Many single-member S-Corp owners still mess this up, especially if they've taken significant distributions or have company debt.
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CosmicCaptain
Honestly, as someone who prepares returns for a living, sometimes the 20+ hour S-Corp returns come down to the clients themselves. Some clients dump unsorted bank statements, unreconciled QuickBooks files, and folders of receipts on you and say "figure it out." If I have to sort through personal and business expenses, fix misclassifications, chase down missing documents, and essentially do a year's worth of bookkeeping before I can even START the tax return... yeah, that can easily push the hours way up.
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Malik Johnson
•This is making me feel guilty lol. I definitely handed my accountant a mess last year. How can I be a better client? Should I be doing monthly reconciliations or something? I use QuickBooks but I'm not great at keeping up with it.
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Chloe Anderson
•@Malik Johnson Don t'feel too guilty - most business owners aren t'trained accountants! Here are some simple things that make a huge difference: 1 Keep) personal and business expenses completely separate - don t'use your business account for personal purchases, 2 Take) photos of receipts immediately and store them digitally even (just in your phone ,)3 Do) a monthly bank reconciliation in QuickBooks - it only takes 15-30 minutes but catches errors early, 4 Set) up automatic rules in QB for recurring transactions like utilities, rent, loan payments, and 5 Send) your accountant a organized summary of any unusual transactions during the year rather than making them guess what things are. Even doing half of these consistently will save your accountant hours and you money!
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Dylan Mitchell
This thread really opened my eyes to how complex S-Corp returns can get! I'm a small business owner considering converting from sole proprietorship to S-Corp for the self-employment tax savings, but now I'm wondering if I'm prepared for the compliance burden. My business is relatively simple - freelance consulting with maybe $150k in revenue, home office, some equipment purchases, and travel expenses. Would an S-Corp election make sense for someone at my level, or am I better off staying as a sole proprietor until I grow larger? The idea of 20+ hour tax prep sounds terrifying, but from what I'm reading here, it seems like that's mainly for much more complex situations with multiple shareholders, messy books, or multi-state operations. Am I understanding this correctly?
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Marcelle Drum
•You're absolutely right that the extreme hour scenarios mainly apply to much more complex situations! At your revenue level with a straightforward consulting business, an S-Corp election could definitely make sense for self-employment tax savings without creating a nightmare compliance burden. For a simple single-member S-Corp like yours would be, you're mainly looking at: filing Form 1120-S (the S-Corp return), issuing yourself a K-1, paying yourself reasonable compensation through payroll, and tracking your basis. The payroll requirement is probably the biggest new compliance piece - you'd need to run payroll for yourself and handle employment taxes. The horror stories in this thread involve multi-member S-Corps, businesses with complex operations across multiple states, poor recordkeeping, or significant asset transactions. Your consulting business shouldn't hit any of those complexity triggers. I'd suggest talking to a CPA about the break-even point for your situation - typically the self-employment tax savings need to exceed the additional compliance costs (payroll processing, additional tax prep fees, etc.). At $150k revenue, you're likely in the sweet spot where it makes financial sense.
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