(720) 333-7274 Mon–Thu 8–4, Fri 8–12 MT · Castle Rock, CO
eCommerce specialty

An accounting firm for Shopify, Amazon, and multi-channel sellers.

Inventory accounting, multi-state sales tax, platform-fee reconciliation, and tax planning that makes sense for online sellers. Built for Denver-area operators doing $250K to $5M.

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Why eCommerce books look nothing like service-business books

If your accountant gave you the same chart of accounts they use for a plumber, your books are wrong. eCommerce has structural differences that show up nowhere else: deferred revenue from gift cards, marketplace facilitator tax, inventory accounting, refund processing, multi-channel platform fees, and ad spend that has to be tied back to the SKUs that actually moved. Get any one of those wrong and your P&L is fiction.

We've worked with Shopify storefronts, Amazon FBA sellers, Etsy operators, multi-brand portfolios, and DTC operations selling into Whole Foods. The patterns we see again and again:

  • The Shopify–QuickBooks sync is not bookkeeping. The native sync maps the daily deposit. It does not break out platform fees, refunds, gift-card liability, or sales tax. A "clean" bank feed is hiding all the detail you need to file accurately.
  • Sales tax is a 50-state problem, not a Colorado problem. South Dakota v. Wayfair changed the rules in 2018. If you cross economic nexus in a state, you have to register and remit there — even if you've never set foot in it.
  • Cost of goods sold is where margin lives or dies. If you can't tell us your blended COGS by month, your "30% margin" is a guess.

What we handle for eCommerce sellers

The work What we deliver
Platform reconciliation Daily/weekly sync from Shopify, Amazon, Etsy, eBay tied back to deposits, with platform fees and refunds broken out
Inventory & COGS Periodic or perpetual inventory accounting with monthly COGS calculation, gross-margin reporting by channel
Multi-state sales tax Nexus tracking, state registrations, monthly/quarterly filings via TaxJar, Avalara, or direct
Ad spend attribution Meta, Google, TikTok ad spend tracked against platform revenue for real ROAS reporting
Year-end tax filing Federal + state returns, S-corp election analysis, owner-comp planning, multi-state apportionment
Cash flow forecasting For sellers with seasonal cycles or planning their next inventory buy
Field note from a 2024 Amazon FBA cleanup

A health-and-wellness brand we onboarded had been pulling Shopify deposits straight to revenue for 18 months. After we backed out platform fees, refunds, and the gift-card liability they should have been deferring, their actual revenue was 9.2% lower than reported — and they'd been overpaying estimated taxes against that inflated number all year. The S-corp election we did at the same time saved them another $14,000 in self-employment tax.

Software we work in for eCommerce

  • Storefronts: Shopify, BigCommerce, WooCommerce, Squarespace Commerce
  • Marketplaces: Amazon (Seller Central + Vendor Central), Etsy, eBay, Walmart Marketplace, Faire
  • Sync & inventory: A2X, Link My Books, Bench, Cin7, DEAR, Inventory Lab
  • Sales tax: TaxJar, Avalara, Anrok, direct state portals
  • General ledger: QuickBooks Online (most common), Xero, NetSuite for $5M+
  • Payment processors: Stripe, Shopify Payments, PayPal, Square

Pricing for eCommerce engagements

We bill hourly, with the typical monthly cost driven by channel count, SKU count, and sales-tax state count.

Stage Typical setup Monthly fee
Single-channel starter Shopify only, <$250K, 1–2 sales-tax states $400 – $650
Multi-channel growth Shopify + Amazon, $250K–$1M, 5–15 sales-tax states $650 – $1,200
Mature operator 3+ channels, $1M+, 20+ sales-tax states, inventory accounting $1,200 – $2,500

Decision matrix: do you need an eCommerce specialist?

If / Then

If you sell on Shopify only, do under $100K, and live in one state — a generalist bookkeeper can handle it (we still recommend a once-a-year tax checkup with a specialist).
If you sell on Amazon FBA, your books need someone who knows what to do with FBA fees, FBA reimbursements, and the inbound-shipping cost line. A generalist will get this wrong.
If you sell across three or more channels or you've passed $500K in revenue, you need a specialist. The accounting complexity has crossed a threshold where mistakes get expensive.

The Bottom Line

Monthly accounting built for online sellers — including the platform fees, sales-tax nexus, and inventory math your last bookkeeper missed.

Get a quote in under a day. We'll tell you up front whether you actually need a specialist or not — most early-stage sellers don't.

Frequently asked questions

Do I need an accountant if I use Shopify and QuickBooks?

The Shopify–QuickBooks sync handles the deposit but not the underlying detail. You still need someone to reconcile platform fees, refunds, gift-card liability, sales tax by state, and COGS. Without that, your "profit" is the deposit minus expenses — not actual margin.

When do I need to register for sales tax in another state?

Economic nexus thresholds vary, but the common trigger is $100,000 in revenue or 200 transactions into a state in a calendar year. Marketplace facilitators (Amazon, Etsy, eBay) collect and remit on your behalf, but your own Shopify storefront does not. We track nexus state-by-state and tell you when to register before you trip a threshold.

How do you handle inventory and COGS?

For sellers with under ~500 SKUs we typically use a periodic inventory method with a quarterly count and adjustment. For larger catalogs we run perpetual inventory through QuickBooks, A2X, or a dedicated inventory system. The right choice depends on margin sensitivity and how often you do physical counts.

Should an Amazon seller be an LLC or S-corp?

Most sellers start as a single-member LLC. The S-corp election usually makes sense once net profit (after a reasonable owner salary) exceeds about $50,000–$60,000 a year. We model both at the discovery call so you can see the actual tax math, not a generic rule.

Reviewed by

Kali Gilliland · Founder & Lead Accountant

Kali Gilliland is the founder of TBA & Associates and has spent more than a decade serving small businesses across the Denver metro and Colorado Springs corridor. She handles everything from monthly bookkeeping to multi-state tax planning, with a long-term client roster that goes back 10+ years.

Ready for an accountant who picks up the phone?

Get a quote in under 24 hours. No long contracts, no jargon — just clean books and honest tax planning from a Denver-area firm trusted by small businesses for more than a decade.