Mainstay Filing is a business formation service built around one idea: a single flat price that covers everything a new company needs, this year and every year after. For $199 a year you get formation document preparation and filing, an EIN, a full year of registered agent service, and — unlike nearly every competitor — preparation and filing of your annual report when it comes due. State fees are passed through at cost and shown before you pay.
Mainstay Filing overview
Most formation services price the way airlines do: a low headline fare, then charges for everything you actually need. Registered agent service typically renews at $119–$249 per year, annual report filing costs another $99–$199 per year, and the checkout process is built to upsell. Mainstay Filing inverts that model. There is one plan, one price, and no add-on menu — the same $199 covers an LLC, corporation, LP, LLP, or nonprofit, in all 50 states, and the renewal price is locked at $199.
The offer is backed by an error-free filing guarantee: if Mainstay makes a mistake on your paperwork, they fix it free.
Mainstay Filing pros & cons
Pros
- One flat $199/year — formation, EIN, registered agent, and annual report filing included
- Annual report is prepared and filed for you, not just a reminder email
- Price-locked renewals — year two costs the same as year one
- No upsells or add-on menus at checkout
- State fees passed through at cost and shown before payment
- Covers every entity type in all 50 states
- Error-free filing guarantee
Cons
- State fees are charged separately (industry standard)
- Single all-in plan — no stripped-down, formation-only tier
Mainstay Filing features
Every subscription includes formation document preparation and filing with your state, EIN registration, a registered agent with a street address in your state (service of process accepted and forwarded), and annual report preparation and filing in each year the subscription renews. Because the annual report is handled inside the same flat rate, there is no separate compliance subscription to track — the one line item covers the whole lifecycle.
Mainstay Filing pricing
| Plan | Price | Includes |
| All-In | $199/year + state fees | Formation filing, EIN, registered agent service, annual report preparation & filing |
Renewals are price-locked at $199/year. For comparison, buying registered agent service ($119–$249/year) and annual report filing ($99–$199/year) separately from typical competitors runs $218–$448 every year.
Mainstay Filing review: Our verdict
Mainstay Filing is our top-ranked formation service. The flat all-in price removes the two costs that surprise most new business owners — registered agent renewals and annual report filing — and the price-locked renewal means the quote you see on day one is the cost in year five. If you want the lowest possible sticker price and are happy to file your own annual reports, a $0-formation service plus a budget registered agent can start cheaper; for everyone who wants compliance genuinely handled, this is the strongest offer available.