BTHE BARATELLI INSTITUTE · Mentoring at Scale
FOR E-COMMERCE SELLERS, CROSS-PLATFORM OPERATORS, AND THE CPAS WHO RECONCILE 1099-Ks

Two compliance landmines every e-com seller hits, usually too late.

Sales tax economic nexus (post-Wayfair, every state has its own threshold and you're liable in 1-50 of them). And the 1099-K threshold dropping to $2,500 in 2025 ($600 thereafter), exposing every casual seller to a federal form that reports GROSS — not net — payments. Both create tax problems most sellers don't notice until they get the audit letter.

$100K
Typical state nexus threshold
$2,500
2025 1099-K threshold
Gross
1099-K reports gross, not net
MFL
Marketplace Facilitator Law
YOUR EXPOSURE
1
Shop & channel mix
2
State revenue
3
Current registrations
4
1099-K reconciliation
5
Compliance verdict
STAGE 1 OF 5

Shop & channel mix

Marketplace Facilitator Laws (MFL) shift sales-tax liability to marketplaces (Amazon, Etsy, Walmart) — they collect and remit. DTC channels (Shopify, your own site) leave you on the hook for nexus, registration, and remittance.

All channels combined. Includes the marketplace channels even though those don't usually create direct nexus liability for you (since the marketplace handles it).
$
Where you operate from. Automatic nexus regardless of revenue. You're already liable here for sales tax on every sale shipped to in-state buyers (subject to MFL carve-out for marketplace channels).
DTC sales create direct nexus + registration liability. You collect sales tax (or your platform like Shopify Tax does it for you, but you still file returns).
%
Marketplace facilitator laws (MFL): the marketplace collects + remits sales tax to the state on your behalf. You generally don't have to register for sales tax in destination states for marketplace sales (with some exceptions: states like NY require registration even if marketplace remits). Tool computes nexus on DTC revenue only.
%
Avalara, TaxJar, Anrok, Stripe Tax handle the calculation + filing. Without software, you're tracking and filing returns manually in every nexus state — quickly impossible above 5-10 states.
CRITICAL: Amazon FBA, ShipBob, ShipMonk, Deliverr — if your inventory is in a state-located warehouse, that creates physical nexus regardless of revenue threshold. Amazon FBA spreads inventory to 20+ states automatically. The "Amazon physical nexus" question is one of the most-debated in e-com tax — most sellers ignore it; states are increasingly aggressive.
The Wayfair decision in one sentence. Pre-2018, you only owed sales tax in states where you had physical presence (warehouse, employee, office). Post-Wayfair (South Dakota v Wayfair), states can require sales-tax collection from any seller above an "economic threshold" — typically $100K revenue OR 200 transactions per year. As of 2026, all 45 states with sales tax have adopted economic nexus rules. Most sellers don't realize they're non-compliant in 5-15 states.
STAGE 2 OF 5

Revenue by destination state (DTC channel)

Enter your DTC revenue (NOT including marketplace sales) shipped to each major destination state. Most sellers can pull this from their Shopify analytics or Stripe dashboard.

Why "DTC only" matters here. When Amazon ships your product to a buyer in California, Amazon (under California\'s MFL) collects + remits the sales tax. You\'re not on the hook for California sales tax for that order. But if you sell that same product directly via Shopify to a California buyer, you\'re responsible. So nexus calculation should use only DTC revenue, not total revenue, for each state.
STAGE 3 OF 5

Current sales-tax registrations

In which states are you currently registered for a sales-tax permit? Tool will compare to nexus exposure.

Count of states where you\'ve obtained a sales-tax permit and file returns. Most first-time sellers register only in their home state. Established sellers register in 10-30+ once nexus expands.
For your most-overdue state: how many months have you been over the nexus threshold without registering? Each month accrues uncollected sales tax + penalty + interest. Many states offer Voluntary Disclosure Agreements (VDA) that limit lookback to 3-4 years vs. unlimited statute.
Used to estimate sales tax owed on uncollected past sales. US weighted average: ~7%. Higher in CA (avg 8.7%), TX (8.2%), NY (8.5%); lower in OR (0%), DE (0%).
%
Most states: ~10-25% penalty + 6-10% annual interest on uncollected sales tax. Total exposure on past non-compliance can be 30-50% on top of the original tax. Tool uses a representative ~25% combined for past liability.
%
Voluntary Disclosure Agreements (VDA) — the cheapest fix. Most states offer VDA programs: you proactively contact the state, disclose your past non-compliance, register, pay back-tax + interest (no penalties), and get limited lookback (typically 3-4 years). The state sometimes waives penalties entirely. Compare to: (1) wait and hope (audit risk + full penalties + unlimited lookback when caught), (2) self-correct without VDA (you pay everything but didn\'t get the leniency). VDAs are the cheapest fix when you have material non-compliance — handled by a sales-tax CPA or consultant ($1,500-5,000 per state).
STAGE 4 OF 5

1099-K reconciliation

The 1099-K threshold dropped from $20,000 / 200 transactions to $5,000 (2024), $2,500 (2025), and $600 (2026 if rules hold). Many casual sellers receive their first-ever 1099-K. Critical: the form reports GROSS payments — not net of fees, refunds, returns, or shipping you absorbed.

Total gross payments processed across all your processors (Stripe, Shopify, PayPal, Amazon, Etsy, Square, etc.). Each processor sends a separate 1099-K. The IRS sees the SUM across all forms.
$
Total refunds processed during the year. Reduces taxable revenue but typically NOT subtracted on the 1099-K itself. Must be reconciled on Schedule C.
$
Sales tax flows through your processor and gets reported on your 1099-K — but it\'s NOT your revenue. Subtract on Schedule C. For marketplace sellers with MFL: typically zero (marketplace handles it). For DTC: equals your sales × avg tax rate.
$
Shipping you charged is part of revenue and IS taxable. But you typically have offsetting shipping COSTS (carrier payments). Both flow through 1099-K. Reconcile both on Schedule C.
$
Why the 1099-K threshold drop matters. A casual reseller who sold $5K of vintage clothing on Etsy in 2025 will receive a 1099-K. The IRS gets a copy. If they don\'t file Schedule C reconciling the $5K to actual income, they\'ll get a CP2000 letter calling the entire $5K taxable. Result: hundreds of thousands of casual sellers will face tax notices in spring 2026 for activity they didn\'t realize was reportable. Reconcile via Schedule C: gross 1099-K → less refunds → less sales tax → less COGS → less other deductions → actual taxable income.
STAGE 5 OF 5 · COMPLIANCE VERDICT

Compliance verdict

—
—
—

State-by-state nexus check (DTC revenue)

Code
State
DTC revenue
Threshold
% of threshold
Status

1099-K reconciliation (Schedule C prep)

Compliance metrics

Recommendations

PAIRS WITH
E-commerce Unit Economics · Etsy/Shopify Take-Rate Tools · Quarterly Estimated Tax
The take-rate tools quantify your platform fees (which you deduct on Schedule C). The Quarterly Estimated Tax tool helps you stay safe-harbored on income tax — sales tax compliance is separate but equally important. Subscribe to the library →
FIRST-TIME ENTREPRENEUR'S GUIDE TO E-COMMERCE

Tax compliance is the part that gets you when you stop paying attention.

State-by-state sales-tax mechanics · Voluntary Disclosure Agreement walkthroughs · 1099-K Schedule C reconciliation · marketplace-facilitator law nuances · Amazon FBA inventory-storage nexus · what to do when a state sends a nexus questionnaire.

We use your email only to send what you requested and occasional Institute updates — never sold, unsubscribe anytime. See our Privacy Policy.

State sales-tax thresholds and rules change frequently. The model uses representative thresholds and rules as of mid-2026. Some states (Alaska, Delaware, Montana, New Hampshire, Oregon) have no statewide sales tax; some (Alaska) have local taxes. Specific state rules vary on: marketplace-facilitator carve-outs, transaction-count thresholds, services taxability, exempt categories. Voluntary Disclosure Agreement programs vary by state — some don\'t offer them. The 1099-K threshold is currently $5,000 for 2024 returns, scheduled to drop to $2,500 in 2025 and $600 in 2026 (subject to legislative change). For sellers above $250K annual revenue across multiple states, engage a sales-tax CPA or consultant (Avalara, TaxJar, Peisner Johnson, etc.) — this is one of the most error-prone areas of e-commerce compliance. This is not professional advice.
WANT THE METHODOLOGY BEHIND THIS TOOL?
This calculator is one chapter of The Business Buyer's Guide.
The tool gives you the answer. The guide gives you the argument — the case law, the worked examples, the negotiation playbook, the cross-check tables, the exception cases. Read the chapter and you can defend your number to a board, a buyer, an examiner, or a counterparty.
The methodology behind this calculator is in e-commerce buyer track of the reference guide.
See the Guide → Browse all 22 guides
PROFESSIONAL DISCLAIMER · PLEASE READ

Educational and informational purposes only. This calculator and any output it produces are intended solely for general educational and decision-support purposes. They do not constitute investment, tax, legal, accounting, appraisal, lending, insurance, or any other professional advice, and they do not create a fiduciary, attorney-client, accountant-client, or advisor-client relationship of any kind.

Estimates based on your inputs. All results are estimates derived from the data and assumptions you provide. Tax law, accounting standards, regulations, market conditions, and the specific facts of your situation can materially change the answer. The Baratelli Institute, its affiliates, and any co-branding professional make no warranty of accuracy, completeness, currency, or fitness for any particular purpose, and disclaim all liability for decisions made in reliance on the output.

Consult your own qualified professionals. Before acting on anything calculated here, consult your own attorney, CPA, financial advisor, appraiser, lender, or other qualified professional licensed in your jurisdiction who has reviewed your specific facts and applicable current law. The Baratelli Institute is a publisher of practitioner reference material. It is not a registered investment adviser, broker-dealer, law firm, accounting firm, appraisal firm, or lender.

Co-branded versions: If a professional advisor's name and contact information appear on this tool, that advisor has elected to make the tool available to clients as a courtesy. Inclusion of an advisor's name does not constitute the advisor's endorsement of any specific result, nor does it transfer professional responsibility for the underlying methodology to that advisor. The disclaimer above applies regardless of co-branding.

Educational references and tools — not legal, tax, accounting, or investment advice, and not a recommendation to buy or sell any security. Consult a qualified professional about your specific situation. © 2026 The Baratelli Institute.