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LLC SchoolhousePlain LLC lessons, one state at a time.

Class 3 · South Dakota

Foreign LLC Registration in South Dakota (2026): a 5-Step Lesson and the 3 Best Services

Report card for registering an LLC from another state in South Dakota in 2026: SD Registered Agent.org ($199), Mainstay Filing ($199) and South Dakota Registered Agent.co ($199), from first place to third. You will find 5 steps below, covering the filing, the $750 fee and what happens next.

Taught by the LLC Schoolhouse editors

This lesson at a glance

State registration fee$750sdsos.gov confirms it, as of October 2026
Home certificateRequiredInclude it
Annual filing$55Annual report
Three-year state total$860Before service fees
Lesson steps5In order

In this lesson

  • Whether South Dakota registration applies to you
  • How the filing works
  • The yearly upkeep
  • How the graded picks compare

If you would like help with the filing

The order follows five published criteria; read how we grade for the details.
First choice

1. SD Registered Agent.org: best for one extra state

Service fee $199, renewal $99 a year

SD Registered Agent.org gets our top grade for South Dakota: $199 added to the state fee, with the agent covered in year one, then $99 a year.

It costs less than Mainstay Filing over three years, and three-year cost is 32% of the grade.

What the price covers

  • Registration prepared and filed
  • One year of agent service

Marks in its favor

  • No agent fee in year one
  • $199 and the state fee
  • Then $99 a year

Where it loses points

  • No help in other states
All fifty states

2. Mainstay Filing: best for a second state and beyond

Service fee $199, renewal $149 a year

For number 2 we picked Mainstay Filing: $199 above the state fee in any state, and the first year of agent service costs nothing.

On three-year cost it falls $100 behind SD Registered Agent.org.

When the free first year ends, the agent costs $149 a year in any state.

What the price covers

  • The registration filing
  • The registered agent costs nothing in year one
  • The same price in any state

Marks in its favor

  • The same fee in every state
  • No agent fee in year one
  • $199 above the state fee

Where it loses points

  • A bigger agent renewal ($149)
South Dakota focus

3. South Dakota Registered Agent.co: best for registering only in South Dakota

Service fee $199, renewal $99 a year

Taking third place is South Dakota Registered Agent.co, where $199 added to the state fee, with the agent covered in year one, then $99 a year.

SD Registered Agent.org and this service charge the same.

What the price covers

  • Registration prepared and filed
  • One year of agent service

Marks in its favor

  • No agent fee in year one
  • $199 and the state fee
  • Then $99 a year

Where it loses points

  • No help in other states

Compare the picks

#ServiceFirst yearFrom year twoThree-year total
1SD Registered Agent.org$199$99/yr$397Visit SD Registered Agent.orgPartner link. We may earn money if you buy.
2Mainstay Filing$199$149/yr$497Visit Mainstay FilingPartner link. We may earn money if you buy.
3South Dakota Registered Agent.co$199$99/yr$397Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
Company prices as posted on November 13, 2026. No row includes the $750 state fee.

The steps

  1. Step
    1

    Check whether registration applies

    If your LLC was formed elsewhere and works in South Dakota, it must first register there as a foreign LLC. Operating unregistered means: What the company signed can still be enforced (SDCL 47-34A-1008(b)).

    Where this comes from: sdlegislature.gov confirms it, as of October 2026

  2. Step
    2

    Obtain your home state's certificate

    Order certificate of Existence.

    Do this step right before you file.

  3. Step
    3

    Line up a South Dakota registered agent

    Every LLC must name a registered agent with an in-state street address. The address has to be an actual street address or rural route box number in South Dakota, plus a South Dakota mailing address if it differs.

    Each of our picks includes the registered agent.

    Where this comes from: sdlegislature.gov confirms it, as of October 2026

  4. Step
    4

    Prepare and file the Application for Certificate of Authority, Foreign Limited Liability Company

    What the South Dakota Secretary of State needs from you is the filing named above and a $750 fee.

    Where this comes from: sdsos.gov confirms it, as of October 2026

  5. Step
    5

    Stay registered

    Look out for the annual report and its $55 fee (1st of the anniversary month).

South Dakota costs by step

WhatWho you payTotal
Foreign registrationState office$750
Annual reportState office$55
Optional serviceThe service$199 to start
Three-year state totalState office$860
The three-year state figure is the filing, the reports due in years two and three and any yearly minimum tax; service fees are separate.

How we graded the South Dakota picks

What settled it was tuition over three years, worth 32% of the grade.

Count the first three years and SD Registered Agent.org comes out at $397, $100 cheaper than Mainstay Filing.

Common questions

How much does South Dakota charge a foreign LLC to register?

$750 to the state. Add $199 if you hire a service.

Which form do I file to register?

Look for the Application for Certificate of Authority, Foreign Limited Liability Company; you deliver it to the South Dakota Secretary of State.

Do I need a certificate from my home state?

Yes: certificate of Existence.

What if the LLC does business there without registering?

What the company signed can still be enforced (SDCL 47-34A-1008(b)).

What is due after registering?

Plan for the annual report, which costs $55.

Which service should handle the registration?

We would pick SD Registered Agent.org, because it files the South Dakota registration for $199 and includes a year of agent service, then renews at $99. After that, Mainstay Filing and South Dakota Registered Agent.co.

Up next

Class references

  1. Want to see South Dakota Secretary of State, Business Services / for yourself? Open sdsos.gov. We confirmed that page in August 2026 before writing the lesson.
  2. Want to see South Dakota Secretary of State, Business Services / for yourself? Open sosenterprise.sd.gov. We confirmed that page in August 2026 before writing the lesson.
  3. Want to see South Dakota yearly filing: Annual report: fee and for yourself? Open sdlegislature.gov. We confirmed that page in October 2026 before writing the lesson.
  4. Want to see South Dakota report due date for yourself? Open sdlegislature.gov. We confirmed that page in August 2026 before writing the lesson.
  5. Want to see SDCL 47-34A-203 for yourself? Open sdlegislature.gov. We confirmed that page in August 2026 before writing the lesson.
  6. Want to see South Dakota formation fee: Filing fee, official source for yourself? Open sdsos.gov. We confirmed that page in October 2026 before writing the lesson.
  7. Want to see South Dakota formation fee: Filing fee, official source for yourself? Open sdlegislature.gov. We confirmed that page in October 2026 before writing the lesson.
  8. Want to see South Dakota registered agent statute for yourself? Open sdlegislature.gov. We confirmed that page in October 2026 before writing the lesson.
  9. Want to see South Dakota Secretary of State, business services for yourself? Open sdsos.gov. We confirmed that page in October 2026 before writing the lesson.
  10. Want to see Foreign LLC application for Certificate of Authority for yourself? Open sdsos.gov. We confirmed that page in October 2026 before writing the lesson.
  11. Want to see SDCL 47-34A-1003, transacting business for yourself? Open sdlegislature.gov. We confirmed that page in October 2026 before writing the lesson.
  12. Want to see SDCL 47-34A-1008, effect of not registering for yourself? Open sdlegislature.gov. We confirmed that page in October 2026 before writing the lesson.
  13. Want to see SDCL 47-34A-1001 to 47-34A-1009, foreign limited liability companies for yourself? Open sdlegislature.gov. We confirmed that page in November 2026 before writing the lesson.
  14. On November 13, 2026 we read the pricing page of SD Registered Agent.org
  15. On November 13, 2026 we read the South Dakota service page of Mainstay Filing
  16. On November 13, 2026 we read the pricing page of South Dakota Registered Agent.co