Virtual Accounting & Tax Strategy for E-commerce Businesses (US-based)

Clean books across every sales channel, inventory and COGS tracking, sales tax support and year-round tax strategy, executed monthly, not scrambled at year-end.

Anomaly CPA advisor in conversation in a bright office

Inc. 5000 company

4x

Recognized as one of the fastest-growing private companies four times.

Our philosophy

Accurate margins on every channel and a tax strategy that runs all year

Accurate margins on every channel, and a documented tax strategy executed monthly, not scrambled together at year-end.

With Anomaly, you get clean, organized financials that track inventory, margins and sales across every channel, plus a documented tax strategy executed monthly instead of rushed at year-end. We handle bookkeeping across marketplaces and storefronts, inventory and cost of goods sold, and the tax planning that matters for online stores: sales tax compliance across states, multi-state exposure, entity structure and quarterly estimated taxes. The result is accurate margins, fewer surprises at tax time, and the confidence that your books and tax strategy are working together as your store scales.

4x

Inc. 5000 company

#1

Tax Strategist in the U.S.

200

Forbes top CPA firms

Expertise

What we do for e-commerce businesses

Channel-level bookkeeping, inventory and COGS tracking, sales tax support and proactive tax strategy, executed monthly, not scrambled at year-end.

Multi-Channel Revenue

Clean books across your website, marketplaces and payment processors, with fees, refunds and payouts matched to sales.

Inventory & COGS

Inventory valuation and cost of goods sold you can rely on, so margins reflect what you actually paid for stock.

Sales Tax & Nexus

Nexus tracking and multi-state sales tax compliance support, so you register and file where you owe.

Profit by SKU

Margin reports by channel and product, so you know which items and platforms are worth scaling.

Tax strategies

Maximizing every dollar with strategic tax planning

Every tax strategy we recommend is built around how online stores operate, from inventory accounting and sales tax to entity structure and multi-state exposure. Here are the four areas we plan for.

Anomaly CPA advisor walking down a glass-walled office corridor

Inventory & COGS Strategy

Choose and apply inventory methods that keep margins accurate and taxable income in check.

Sales Tax & Nexus

Track economic nexus thresholds, and register and file where you owe, before small gaps become large liabilities.

Entity & Owner Compensation

Evaluate the right structure and an efficient way to pay yourself as profits grow.

Multi-State & Growth Planning

Manage state filing exposure and plan reinvestment, financing and exit options as the store grows.

How we work

Tailored tax solutions for e-commerce businesses

Don't settle for a tax planning process that just skims the surface. We start with a comprehensive review of your store, then deliver high-impact, proactive strategies tailored to your situation.

Two people reviewing a document together at a table on an outdoor terrace

Identify

We review your channels, inventory model, entity and states to identify the tax strategies that actually apply to your store.

Implement

We build each strategy into your current books and sales systems on the fly, so inventory, sales tax and estimates are tracked month to month.

Report

We make sure every strategy is reported correctly on your returns, with the documentation to support it.

Accounting services

Accounting Services for E-commerce Businesses

Multiple sales channels, marketplace fees, returns, inventory and sales tax across states create a different equation for every online store. Whether you sell on your own site, marketplaces or both, our team brings organized accounting and practical, hands-on insight.

Core Bookkeeping

Monthly close, channel-level revenue and fees, and clean, GAAP-ready financials. Payouts, refunds and chargebacks are reconciled, so your books match your platforms.

Inventory & Fixed Assets

Inventory tracking, COGS, capitalization policies and depreciation schedules, so the stock on hand and your balance sheet agree.

Reporting You'll Trust

Margin reports by channel and product, quarterly reviews and organized documentation. You can see what each channel really earns after fees.

Tailored to Your Goals

Structured around your channels, inventory model and tax strategy, whether you sell on your own site, marketplaces or both.

Fast, Pro Support

A responsive team with fast turnaround, so there is no waiting and no delays during your busiest season.

Packages

Pick a Plan That Fits Your Store

Year-round tax strategy and monthly accounting for online stores. Choose one or combine both.

Concierge Tax

Proactive tax strategy built around how online stores operate, from inventory to sales tax nexus.

Starting from
$450
/month

Dedicated Tax Project Manager

Mid-Year & Year-End Check-In Meetings

Tax Projections & Estimated Tax Payments

Inventory, COGS and sales tax nexus planning

Tax Return Preparation

Core Accounting

Monthly bookkeeping with channel-level revenue and fees, reconciled to your platforms.

Starting from
$400
/month

Monthly close and reconciliations

Payouts, refunds and chargebacks reconciled

Inventory tracking and COGS

Reporting and dashboard with Concierge accounting, from $800/month

Client voices

Anomaly CPA’s client victories in the spotlight

Innovative business owners and investors across the globe benefit from our unique tax strategy and cloud accounting experience allowing them to stay ahead of the curve.

“

I discovered them through some research on Google, actually.
I had just moved to Massachusetts, and I needed a Massachusetts accountant, somebody to come and partner with me.

I’ve been using them for about two years now.
They are great partners.

They really support me in my business, and I highly recommend them.

I feel they can support any industry with all their accounting and tax needs.

‍

C.Kay International
“

I’ve been a client since day one,
and I’m just so proud of him,
seeing him build this up.

Now he’s helping so many people—
so many entrepreneurs,
so many businesses,
so many investors,
so many individuals and companies. It’s been incredible.

I’ve been working with him and his team
for, yeah, must be four years now. And I would say, if you’re an entrepreneur,
you own businesses,
or you’re a high earner
and you have investments like real estate,
working with Greg is an absolute no-brainer.

They’re forward-thinking.
They’re cutting-edge.
They’re leaders in the space.

I know personally, for me,
they’ve saved me a lot of money,
which has been able to add to my net worth.

I’ve saved way more than they’ve cost,
or the investment in them.And it’s so worth it.
So much so.I’ve recommended dozens of people to them.

Wade Critides | Lifestyle Entrepreneur
“

I would wholeheartedly recommend Greg O’Brien and his entire team to any small business or mid-sized business owner looking for help.

We don’t have the resources, and often don’t have the budgets, to bring on staff full-time.

Honestly, Greg and his team have been the next best thing.

John Guilfoil Public Relations
“

The biggest difference that we noticed right away was that there were all these things that we could be taking advantage of.

We could be way more strategic with how we were filing, what strategies we had in place, and what things had been ruled on from a tax law perspective.

My favorite part about it is, at the highest level— because there are tiers that you can work with the team through— but at the highest level, you’re fully supported.

Your accounting is taken care of. All of your tax strategy is taken care of. Basically anything you would need on the back end, money-wise, you’re taken care of.

That even includes if an audit were to come up or something like that. You have support with all of that. Love it. So grateful.

Nexus Family Chiropractic
“

"Anomaly, has been INSTRUMENTAL to the success of our start-up business. Their knowledge, expertise, and due diligence in the accounting field gives us the confidence that our books will always be in good hands as we continue to focus on other pertinent business matters. I would recommend Anomaly to anyone looking for a fantastic service on a budget! Thank you for being awesome!"

Brian Megill | Host Events Inc.
“

"Anomaly provides a professional and tailored approach to achieve the desired outcome for clients and we couldn’t be happier with the quality of his services. They've helped us manage through the first year of our new company and taken the stress out of dealing with multiple vendors, agencies and tax authorities making year one seamless for our business. We look forward to another successful year and would highly recommend their services!"

Jay Carlington
“

"I would recommend Anomaly to anyone. They have been an extremely valuable asset to our business and acts as an extension of our team. We began working with Anomaly almost 2 years ago and it was a great decision. They are extremely responsive and I would highly recommend their services to anyone."

Dan Bresciani
“

"Anomaly helped me out with starting my own business. I could tell right away that they were extremely knowledgeable and passionate about helping their clients navigate the complex world of taxes and creating effective strategies to reach their goals."

‍

Mark Perlberg

Award-winning impact: Recognized excellence in client services

Our team has been recognized for our impact
and services to clients. Recent awards include: Greg O'Brien (3x) and John Malone (2x) as 40 Under 40, AccountingToday Top 10 Firms for Tech, the #1 Tax Strategist of the Year Award by the American Institute of Certified Tax Planners & Forbes Magazine Top 200 CPA Firms.

2026 Forbes Best-in-State Top CPA

2025 Forbes Best-in-State Top CPA

2024 Forbes Top 200 CPA Firms

Two CPA Practice Advisor logos: left side shows '40 Under 40' in purple and gray; right side shows '20NTY Under 40 Influencer' in dark red and gray.

2022 CPA Practice Advisor "40 Under 40" professionals who have emerged as leaders in the profession.

Accounting Today 2022 Best Firms for Technology badge.

2022 Accounting Today Best Firms for Technology

2021 Concierge Accounting Firm of the Year

Gold seal emblem with initials CTP and text Certified Tax Planner around the edge.

2020 AICTC Tax Planner of the Year National Finalist

E-commerce FAQs

Frequently Asked Questions About Accounting & Tax Strategy for E-commerce Businesses

How should I pay myself as the owner of an online store?

It depends on your entity and your profit. We help you choose a structure and an efficient mix of salary and distributions, and we plan quarterly estimates so your tax bill is predictable.

Can you show me profit by product and by channel?

Yes. We set up your books to track revenue, fees and costs by channel and product, then deliver margin reports you can use to decide what to restock, reprice or drop.

Do I have to collect sales tax in other states?

Possibly. Once your sales in a state pass its economic nexus threshold, you may need to register, collect and file there. We track your sales by state and tell you when a threshold is getting close.

How should an online store account for inventory and cost of goods sold?

We track inventory purchases, landed costs and cost of goods sold so your margins reflect what you actually paid for stock. We also help you choose an inventory method that fits your business and holds up on your tax return.

How do you keep the books for multiple sales channels and marketplaces?

We bring sales, fees, refunds and payouts from every channel and payment processor into one set of books. Each channel is tracked separately, so you can see what it really earns after fees.

How do I get started with Anomaly CPA as an e-commerce business?

Start with a short intro call. We look at your sales channels, inventory model and current books, then recommend a scope of work and pricing that fits your store.

From the blog

Guides & insights for e-commerce businesses

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Built for e-commerce businesses

Ready to partner with a virtual CPA for your online store?

A short call with our team, no prep needed.

63
five-star reviews
4x
Inc. 5000 company
50
states served, fully remote
Intro call
A 30-minute intro call with our team
We learn about your business and goals
You learn how working with Anomaly CPA works
No prep, no pitch deck, no obligation
Or call 781 694 2203 · Boston, MA