3 Best Foreign Registration Services in South Dakota (2026)
LLC Review Desk's 2026 picks for foreign registration services in South Dakota, favorite first, are South Dakota Registered Agent.co ($199), Mainstay Filing ($199) and SD Registered Agent.org ($199). South Dakota Registered Agent.co is our favorite, because it's $199 plus the state fee, with your first registered agent year included, then $99 a year for the agent.
By the LLC Review Desk editorial team
Position 1
Best here
1. South Dakota Registered Agent.co: best for companies adding only South Dakota
You pay $199 plus the state fee, then $99 a year for the agent
Our score
9.2out of 10
9.2 out of 10
Our favorite is South Dakota Registered Agent.co, because registering in South Dakota costs $199 and covers year one as your agent, then $99 a year.
You get a street address in the state for your registered office, and any papers served on the company are scanned into your online account.
You pay less over three years than with Mainstay Filing.
In the price
Foreign registration done for you
A year of registered agent service at the outset
What we like
A $199 service price plus the registration fee
Your first year as registered agent is free
$99 a year for the agent from year two
Trade-offs
South Dakota only; your home state needs its own agent
2. Mainstay Filing: best for owners working in more than one state
You pay $199 plus the state fee ($949 at checkout), then $149 a year for the agent
Our score
8.7out of 10
8.7 out of 10
Coming in second is Mainstay Filing, because $199 gets the South Dakota registration filed, year one as registered agent costs nothing, and after that it's $149 a year.
Year one as agent costs nothing; every later year is $149, in any state.
South Dakota Registered Agent.co is $100 cheaper over three years, so Mainstay Filing comes second on cost.
In the price
Your registration filing, taken care of
The first registered agent year at no charge
Papers served on the company are scanned and uploaded the same business day, free
What we like
$199 for the service, plus the state's fee
Same-business-day scans of papers served on the company, no charge
The same price in all fifty states
Your first year of registered agent service is free
Trade-offs
After year one the agent is $149 a year, $50 more than South Dakota Registered Agent.co
LLC Review Desk gives each score out of 10 itself, based on the criteria on How we rank. No customer ratings are involved.
What South Dakota foreign registration services cost in 2026: year one, renewals and three years
Service
First year
Second year
Third year
Three-year total
Agent covered in year one
South Dakota Registered Agent.co
$199
$99
$99
$397
Included
Mainstay Filing
$199
$149
$149
$497
Free
SD Registered Agent.org
$199
$99
$99
$397
Included
We took each price from the company's own pages on November 12, 2026. On top of every row, South Dakota charges a $750 registration fee, which isn't in these totals.
What decided the order
Here's how we scored it: three-year cost and filings in the price are worth 29% each, and renewal price, state fit and up-front totals split the other 42%. In South Dakota, three-year cost made the difference.
South Dakota Registered Agent.co comes to $397 over three years, which is $100 less than Mainstay Filing. Both include the first year, so the renewal price decided it.
You can read every criterion and weight on How we rank.
Registering a foreign LLC in South Dakota: fee, form and who to send it to
You register through the South Dakota Secretary of State, using the Application for Certificate of Authority, Foreign Limited Liability Company. The state charges $750. South Dakota also wants certificate of Existence.
After that, plan on the annual report each cycle ($55) by 1st of the anniversary month.
Get these ready first
Certificate of Existence.
Your company's full legal name, exactly as registered at home, and the date it was formed there.
A registered agent with a street address in the state. Any service on this page can do it.
The $750 state fee to pay with the filing.
A reminder for yourself about the annual report and its $55 fee.
What happens if you skip South Dakota registration
Its contracts still stand (SDCL 47-34A-1008(b)).
Your questions about South Dakota foreign registration services
Do I have to register my out-of-state LLC in South Dakota?
If it does business there, yes.
What does registering a foreign LLC in South Dakota come to?
The state charges $750, and services charge $199.
Does South Dakota want paperwork from my home state?
It does: certificate of Existence.
Do I still need a registered agent after I register?
Yes. You keep a registered agent with a street address in the state as long as the company stays registered.
Which foreign registration services did we review here?
South Dakota Registered Agent.co ($199), Mainstay Filing ($199) and SD Registered Agent.org ($199), with our favorite first.
Who's the best choice for foreign registration in South Dakota?
South Dakota Registered Agent.co, because $199 beyond the state fee gets you registered in South Dakota, and the agent renews at $99.