Best LLC for a marketing or digital agency: pass-through spend and contractors

Agencies are structurally simple and operationally treacherous. There is no inventory, no product liability, no marketplace deciding your fate. What there is instead is a large amount of money moving through the business that was never yours, and a workforce whose employment status you have chosen rather than confirmed.

The short answer

An LLC. Single-member and disregarded if you own it outright; multi-member taxed as a partnership if you have a co-founder. Elect S-corp status when net profit is durable and past roughly $90,000 — the arithmetic is the same as for any service business, and there is a worked table on the freelancer guide.

The reason this page exists is not the entity. It is the three things that make an agency different from a freelancer with staff.

Pass-through ad spend distorts everything downstream

If you buy media on your client's behalf using your card and invoice it back, that spend runs through your books. A media-buying agency with $200,000 of genuine service revenue can show $2,000,000 of gross receipts. That number then leaks into places that cost you money:

Two ways out, and they are contract choices rather than entity choices. Either the client pays the platform directly and you never touch the money, or your agreement is explicit that you are acting as agent and the spend is a reimbursement rather than revenue. Both should be settled in writing before the first invoice, not reconstructed by an accountant afterwards.

Your contractors are the biggest unpriced liability

Agencies are built on contractors: designers, editors, media buyers, chat teams, developers. Some of them are contractors. Some of them work only for you, on your schedule, with your accounts and your tooling, and have done for two years — and those are employees in fact, whatever the agreement says.

Misclassification exposure lands on you, not on them: back employment taxes, penalties, and interest, plus whatever your state adds. The tests differ between the IRS and individual states, and several states apply a considerably stricter standard than the federal one. It is entirely possible to be correct federally and wrong locally.

• Control is the theme running through every test. Who decides how the work is done, when, and with what.
• Exclusivity is the loudest single signal. A contractor with one client for years is the profile that gets reclassified.
• Overseas contractors are a different question, not an absent one. US employment classification generally does not reach them, but their own countries' rules do, and permanent-establishment risk arrives with sufficiently embedded staff.
• Paperwork is necessary and insufficient. A signed contractor agreement plus a W-9 or W-8BEN is the floor, not the answer.

Liability is professional, not physical

Nobody is injured by a media plan. What happens instead is that a campaign underperforms, an ad account gets banned, a claim in an ad draws a regulator, or a data handling arrangement turns out not to comply. The LLC keeps those claims away from your personal assets; two other things keep them smaller:

• Errors and omissions cover, which many mid-size clients will require anyway.
• A limitation of liability clause capped at fees paid, which is the single most valuable line in an agency contract and the one clients most often try to strike.

If you make performance claims in your own marketing, they are subject to the same advertising rules you are advising clients about. Agencies get caught by this more often than you would expect.

AI does not change the structure

An AI automation agency is an agency. The delivery is different, the margin is usually better, and the pitch is newer — but on every axis that decides an entity (revenue character, sales-tax class, liability profile, licensing, classification, S-corp math) the answer is the one above. Where it does differ slightly is worth naming: you are more likely to be reselling third-party model capacity, which is a pass-through cost with the same accounting question as media spend, and your contracts should be explicit about who owns the automations you build.

If you are not a US person

• No S-corp election — Section 1361 excludes non-resident alien shareholders.
• Form 5472 with a pro-forma Form 1120 annually for a foreign-owned single-member LLC, at a $25,000 penalty for failure to file.
• Your US-based contractors are the fact that most often creates effectively connected income. An agency run entirely from abroad with foreign contractors is a materially different tax position from the same agency with two US employees.
• Payments to foreign contractors need documentation — collect a W-8BEN before the first payment, not at year end.

When to revisit