What the IRS Sees When You Sell Online
Every sale you make leaves a documented trail. Amazon, Shopify, PayPal, and Stripe all report payment data directly to the IRS using Form 1099-K.
Following the passage of the One Big Beautiful Bill Act (OBBBA), the federal reporting threshold has been permanently set to $20,000 in payments AND more than 200 transactions per platform per year. If you're based in Vermont, Maryland, Virginia, or Massachusetts, your state threshold is $600.
What this means in practice: if the IRS sees $150,000 in gross receipts reported on your 1099-K but your return shows $120,000, there's a $30,000 gap that needs to be explained. That explanation might be completely legitimate — returns, platform fees, chargebacks — but without clean records, you can't demonstrate it.
Underpayment penalties add up quickly:
5% per month on unpaid taxes, up to 25% total
20% accuracy-related penalty if the IRS determines carelessness
7% annual interest, compounded daily, on any unpaid balance
The IRS can review returns going back 3 years in standard situations. If income was underreported by 25% or more, that window extends to 6 years. For unfiled returns, there's no time limit. Organized records are your protection in any of these scenarios.
Real Examples of What's at Stake
Jeff's online store had $39,000 in Stripe deposits that were never recorded. It wasn't intentional — they simply weren't captured. When the IRS reviewed his return, he owed back taxes and penalties on income that had been sitting in his own bank account.
Carmen had a different experience. The IRS initially told her she owed $46,500 based on discrepancies in her reports. She invested $2,100 in an accountant to review everything thoroughly. The actual amount owed: $412. Clean documentation turned a five-figure problem into a manageable one.
The pattern shows up in larger businesses too. Ecomom, a well-funded eCommerce brand that raised $12 million from investors, closed in 2013 after losing money on every order without realizing it. For every $60 order, their shipping costs ran $89. The reports were available — they just weren't being read carefully. A consistent monthly review of the financials would have surfaced the problem early enough to act on it.
Studies suggest that 66% of small business audits stem from bookkeeping errors — not intentional fraud, but gaps in records.
Each Platform Has Its Own Accounting Challenges
Amazon FBA is the most complex. Referral fees, FBA fulfillment fees, storage fees, advertising charges, reimbursements, and reserve holds all move through your account — often within the same settlement. According to third-party auditing firms, approximately 60–70% of FBA sellers experience overcharges due to incorrect product weight or dimension classifications and miscalculated storage durations. Sellers who reconcile their fee reports regularly tend to recover these hidden margins — making it one of the higher-return habits in eCommerce bookkeeping.
Shopify deposits less than your gross sales because payment processing fees (approximately 3% + $0.30 per transaction) and returns are already deducted. Payouts also take 3–7 business days, which means December sales can arrive as January deposits — creating a timing mismatch that affects your monthly books.
Etsy layers multiple fees on each transaction: $0.20 to list, 6.5% transaction fee, 3% + $0.25 for payment processing, and 2.5% for currency conversion on international sales. Sellers above $10,000 in annual sales are also enrolled in Etsy's offsite ads program at 15% of attributed sales.
eBay combines multiple transactions into consolidated deposits and charges approximately 13.25% + $0.30 per order. A sale completed March 23 might not hit your bank until April 7.
The most common mistake across all platforms: recording the deposit as your revenue. The deposit is not your revenue — it's your revenue minus whatever the platform already deducted. If you record the net deposit without separating out fees, your gross revenue is understated, your expenses are invisible, and your margin calculations are wrong.
If you sell internationally, currency exchange can cost 3–5% of affected revenue. At significant volume, that adds up to a real number worth tracking.
Sales Tax: More Complex Than It Used to Be
Before 2018, sales tax only applied where you had a physical presence. The Supreme Court's ruling in South Dakota v. Wayfair changed that. Now, the majority of states can require you to collect sales tax based on your sales volume alone.
Most states use $100,000 in annual sales as the threshold. Some states differ:
California and Texas: $500,000
New York: $500,000 AND 100+ transactions
Kansas: No minimum threshold
Note: These thresholds reflect state rules as of 2025. Economic nexus laws are updated frequently — confirm current thresholds before filing.
Amazon FBA sellers have an additional layer: inventory stored in fulfillment centers creates physical nexus in those states, independent of your sales volume.
Penalties for non-compliance vary by state:
1–30% of taxes owed, depending on the state
Texas: 5% for payments 1–30 days late, 10% after 30 days
Georgia: Up to 50% in cases involving fraud
Multichannel sellers may have obligations in 15 or more states, each with different filing schedules. Staying organized is the only way to stay compliant.
Building a Bookkeeping System That Works
How often should you review your books?
Monthly Sales Volume | Recommended Frequency |
|---|---|
Under 100 orders | Monthly (2–3 hours) |
100–1,000 orders | Weekly (1–2 hours) |
Over 1,000 orders | Daily (30–60 minutes) |
At minimum, a monthly review catches most issues before they compound.
What to review each time:
Business bank account
Business credit cards
Each platform's settlement reports
Sales by channel
Platform fees
Inventory levels
Sales tax collected and owed
Returns and chargebacks
The most important structural habit: use clearing accounts for each platform rather than recording deposits directly as revenue. The flow should be: gross sales → subtract fees → result is the deposit. This keeps every component visible and makes reconciliation straightforward.
The right tools make this manageable:
For accounting:
QuickBooks Online — the most widely used platform for small business accounting in the U.S., with direct integration support for eCommerce
For connecting your platforms:
Link My Books — designed specifically for eCommerce sellers, it connects Amazon, Shopify, Etsy, and eBay directly to QuickBooks and automatically categorizes each component of your settlements: gross sales, fees, refunds, taxes collected, and more
Together, these tools can reduce what used to take 15–20 hours per month to 3–5 hours — and significantly improve accuracy in the process.
How to Protect Yourself in an Audit
The IRS closed 505,514 audits in 2024, collecting over $29 billion in additional taxes, followed by 497,621 audits and $26.8 billion in 2025. The overall individual audit rate is approximately 0.38% — but self-employed individuals filing Schedule C face a notably higher examination rate, typically between 0.9% and 1.3%. As an eCommerce seller reporting business income, that elevated risk is worth planning for — which is exactly why clean, well-documented books make such a practical difference.
Most IRS audits are conducted by mail. You receive a letter, and you're asked to substantiate specific numbers. Common triggers include:
Deposits that don't match reported income
Deductions that are unusually high relative to income
Consistent annual losses
Heavy home office or vehicle deductions
When your books are organized, an audit is manageable. You show that each deposit ties to a documented source, and each deduction has a corresponding receipt. When the numbers all connect, the review moves quickly.
One seller faced an audit claiming she owed $32,500 in unsubstantiated deductions. Her records had been kept informally — notes on paper, no meal receipts, and a vehicle claimed at 100% business use. After reconstructing her records as thoroughly as possible, the IRS assessed $2,300 — saving nearly $14,000 through documentation that was rebuilt after the fact. Organized records from the start would have made the process even cleaner.
Record retention guidelines:
Situation | Keep For |
|---|---|
Standard records | 3 years |
Employee records | 4 years |
Significant underreporting (25%+) | 6 years |
Bad debts or worthless stocks | 7 years |
Property records | Duration of ownership + 3 years |
What Clean Books Make Possible
Organized financials aren't just about protection — they're a business asset.
They make your business sellable. Buyers require clean, auditable financial records. An eCommerce business with well-maintained books is significantly easier to value and sell than one with unclear records.
They support financing. Banks and investors review financial statements before lending. If your books don't clearly show your revenue, expenses, and margins, financing conversations become much harder.
They inform better decisions. If Ecomom had been reviewing their per-order costs monthly, they would have seen the shipping problem early enough to restructure pricing or fulfillment before the losses became unrecoverable.
They reduce your tax bill. Deductions like Section 179 (up to $2,500,000 in qualifying equipment for 2025) require documentation. Clean records mean you capture every deduction you're entitled to — not just the ones that are easy to remember.
Businesses that reconcile their books consistently tend to recover overcharged fees, identify underperforming products early, catch cash flow issues before they become critical, and move through audits without disruption.
How Tall Oak Advisors Can Help
eCommerce accounting has a learning curve that most general accountants haven't had reason to climb. Amazon settlement reports, Shopify payout timing, FBA fee structures, multi-state nexus — these aren't concepts that come up in most bookkeeping practices.
At Tall Oak Advisors, this is all we do. We work with eCommerce sellers — Amazon FBA businesses, Shopify store owners, and multichannel operators who need a team that already understands their platforms, their reports, and their challenges.
Our team uses Link My Books and QuickBooks to keep your books accurate, your fees reconciled, and your records ready for whatever comes next — whether that's a quarterly review, a financing conversation, or a clean tax filing.
Ready to get your books working for you? Schedule a free consultation and let's look at your setup together.
This article is for educational purposes only and does not constitute tax, legal, or financial advice. Tax laws, platform policies, and compliance requirements change frequently. Always consult a qualified tax professional for guidance specific to your situation.
