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Formation Scorecard

Foreign registration scorecard · South Dakota

3 Best Foreign Registration Services in South Dakota (2026)

On the Formation Scorecard 2026 scorecard for foreign registration services in South Dakota the order reads South Dakota Registered Agent.co ($199), Mainstay Filing ($199) and SD Registered Agent.org ($199). South Dakota Registered Agent.co posts the top score: the South Dakota registration at $199, first agent year included, then $99 a year.
Researched and written by the Formation Scorecard editorial team
Rank #1 Top pick on this page

1. South Dakota Registered Agent.co: best for companies that add just South Dakota

9.4 Editor score out of 10
$199 service fee plus the state fee; agent $99 yearly from year two

South Dakota Registered Agent.co leads the card: $199 beyond the state fee to register in South Dakota, agent renewing at $99.

The plan puts the company at an in-state street address and scans papers served on it to your online account.

It pulls ahead of Mainstay Filing on three-year cost.

What you get

  • Filing with the state
  • Year-one registered agent service included

Strengths

  • First-year registered agent service included
  • $99 yearly for the agent after year one
  • Files the registration for $199 plus the state fee

Watch for

  • Limited to South Dakota; your home state still needs an agent
  • $99 extra for the EIN application
Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy. South Dakota Registered Agent.co: the full write-up
Rank #2 Fifty-state coverage

2. Mainstay Filing: best for companies spread across states

9.2 Editor score out of 10
$199 service fee, $949 due at checkout including the state fee; agent $149 yearly from year two

Mainstay Filing takes second spot: it files the South Dakota registration for $199 and acts as your registered agent, free for year one and $149 a year after.

The agent is free in year one and $149 a year after that, wherever the company registers.

South Dakota Registered Agent.co undercuts Mainstay Filing by $100 over three years, and that gap costs Mainstay points on cost.

What you get

  • Registration prepared and submitted
  • The first registered agent year at no charge
  • Served papers scanned and uploaded the day they arrive, free

Strengths

  • $199 service fee, with the state fee on top
  • Same price across all fifty states
  • Registered agent free for year one
  • Served papers scanned on the day they arrive, free

Watch for

  • Agent renewal of $149 is $50 more than South Dakota Registered Agent.co charges
Visit Mainstay FilingPartner link. We may earn money if you buy. Mainstay Filing: the full write-up
Rank #3 Best for a South Dakota-only company

3. SD Registered Agent.org: best for registrations in South Dakota only

9.1 Editor score out of 10
$199 service fee plus the state fee; agent $99 yearly from year two

SD Registered Agent.org takes third spot: $199 beyond the state fee to register in South Dakota, agent renewing at $99.

The plan puts the company at an in-state street address and scans papers served on it to your online account.

Price for price and feature for feature, South Dakota Registered Agent.co and SD Registered Agent.org match, which leaves the order between them a narrow call.

What you get

  • Filing with the state
  • Year-one registered agent service included

Strengths

  • Registration at $199, with the state fee added
  • Includes the first registered agent year
  • Then $99 a year to keep the agent

Watch for

  • Limited to South Dakota; your home state still needs an agent
  • $99 extra for the EIN application
Visit SD Registered Agent.orgPartner link. We may earn money if you buy. SD Registered Agent.org: the full write-up

The 3 entries on one card

Place Service Card score Service fee Year two Best for Go
1 South Dakota Registered Agent.co 9.4 $199 $99/yr The lowest agent renewal we rank here Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
2 Mainstay Filing 9.2 $199 $149/yr Companies spread over several states Visit Mainstay FilingPartner link. We may earn money if you buy.
3 SD Registered Agent.org 9.1 $199 $99/yr The lowest agent renewal we rank here Visit SD Registered Agent.orgPartner link. We may earn money if you buy.

Every number out of 10 is an editorial mark from Formation Scorecard, produced with the criteria on How we rank, not a customer rating.

South Dakota foreign registration service cost in 2026: first year, renewal and the three-year tally

Service First year Second year Third year Three-year tally Agent paid 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

Each price comes from the company's own site, read on November 12, 2026. Add South Dakota's $750 registration fee to each row; the tally above leaves it out.

What broke the tie

Formation Scorecard scores cost across three years and coverage of the price at 25% each. Renewal terms, state-by-state fit and pricing clarity account for the other 50%. In South Dakota the tie was broken by cost across three years.

South Dakota Registered Agent.co tallies $397 across three years, $100 below Mainstay Filing. Both include the first agent year, so the renewal price after year one broke the tie.

Every criterion and weight appears on How we rank.

Foreign LLC registration in South Dakota: fee, form and filing office

An outside company registers by sending the Application for Certificate of Authority, Foreign Limited Liability Company to the South Dakota Secretary of State, with a $750 state fee. South Dakota additionally requires certificate of Existence.

Once registered, the company files the annual report ($55), due 1st of the anniversary month.

Gather these before filing

  • Certificate of Existence.
  • The company name exactly as the home state has it, plus the date it was formed.
  • An in-state registered agent; any service on this card can fill that role.
  • The state fee of $750, sent in with the filing.
  • A calendar date for the annual report and its $55 fee.

The price of ignoring South Dakota registration

Its contracts remain valid (SDCL 47-34A-1008(b)).

South Dakota foreign registration service: quick questions

Does South Dakota make an outside LLC register before operating?

Yes, when the company does business there.

What will foreign registration run in South Dakota?

Expect $750 for the state plus $199 for the service.

Is a home-state certificate part of the South Dakota filing?

Yes, the state wants certificate of Existence.

Does a registered company still need a registered agent?

Yes, a registered agent with an in-state street address has to stay on file.

Which foreign registration services sit on this card?

South Dakota Registered Agent.co ($199), Mainstay Filing ($199) and SD Registered Agent.org ($199), top to bottom.

Which foreign registration service leads the card for South Dakota?

South Dakota Registered Agent.co, since $199 plus the state fee and a year of registered agent service, then $99 yearly for the agent.

Keep reading

Where the figures come from

  1. South Dakota Secretary of State, Business Services / Corporations Division, as of August 2026
  2. South Dakota Secretary of State, Business Services / Corporations Division, as of August 2026
  3. South Dakota yearly filing: Annual report: fee and how, official source, as of October 2026
  4. South Dakota report due date, as of August 2026
  5. SDCL 47-34A-203, as of August 2026
  6. South Dakota formation fee: Filing fee, official source, as of October 2026
  7. South Dakota formation fee: Filing fee, official source, as of October 2026
  8. South Dakota registered agent statute, as of October 2026
  9. South Dakota Secretary of State, business services, as of October 2026
  10. Foreign LLC application for Certificate of Authority, as of October 2026
  11. SDCL 47-34A-1003, transacting business, as of October 2026
  12. SDCL 47-34A-1008, effect of not registering, as of October 2026
  13. SDCL 47-34A-1001 to 47-34A-1009, foreign limited liability companies, as of November 2026
  14. Read on November 12, 2026: pricing and service pages for South Dakota Registered Agent.co
  15. Read on November 12, 2026: South Dakota service page for Mainstay Filing
  16. Read on November 12, 2026: pricing and service pages for SD Registered Agent.org