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Formation ClassClass is in session: LLC paperwork, state by state.

Class 3 · South Dakota

Foreign LLC Registration Class, South Dakota (2026): 5 Assignments and the 3 Best Services

Pop quiz answer for South Dakota in 2026: Mainstay Filing ($199), South Dakota Registered Agent.co ($199) and SD Registered Agent.org ($199) are the services to use for registering an LLC from another state, best grade first. The class's 5 assignments cover the filing, the $750 fee and what you owe afterward.

Taught by the Formation Class faculty

Need-to-know facts

Fee at the state office$750Check the textbook page: sdsos.gov (read October 2026)
Certificate from your home stateRequiredAttached to the filing
Annual report$55Annual report
Three-year state cost$860Registration, reports and any minimum tax
Assignment count5One by one

What this class teaches

  • When an LLC from elsewhere must register in South Dakota
  • How the filing gets made
  • Staying in good standing
  • How the picks stack up

The South Dakota honor roll

The teacher's five criteria are on how we grade, and they decide the order.
Top of the class

1. Mainstay Filing: best for one provider for both states

$199 to register, $149 per year after

Mainstay Filing gets first place, and the reason is that it files the South Dakota registration for $199 plus the state fee, and the first agent year is free.

You pay $100 extra across three years compared with South Dakota Registered Agent.co, and you keep less of the paperwork.

Agent service past the first year is $149 yearly.

Covered by the tuition

  • Filing made with the state
  • The registered agent costs nothing in year one
  • Covers all fifty states

Strengths

  • A $199 service charge
  • The same fee in every state
  • Registered agent is free in year one

Weak spots

  • A pricier agent renewal ($149)
South Dakota specialist

2. South Dakota Registered Agent.co: best for one extra state

$199 to register, $99 per year after

South Dakota Registered Agent.co lands in second place: $199 above the state fee to register, then $99 a year.

Covered by the tuition

  • The South Dakota registration, prepared and sent
  • One year of agent service is part of the price

Strengths

  • Then $99 per year
  • $199 above the state fee
  • No agent fee in year one

Weak spots

  • Serves South Dakota alone
South Dakota specialist

3. SD Registered Agent.org: best for another South Dakota option

$199 to register, $99 per year after

SD Registered Agent.org lands in third place: $199 above the state fee to register, then $99 a year.

South Dakota Registered Agent.co and this service cost the same.

Covered by the tuition

  • The South Dakota registration, prepared and sent
  • One year of agent service is part of the price

Strengths

  • $199 above the state fee
  • No agent fee in year one
  • Then $99 per year

Weak spots

  • Serves South Dakota alone

The South Dakota grades compared

#ServiceFirst yearFrom year twoThree-year total
1Mainstay Filing$199$149/yr$497Visit Mainstay FilingPartner link. We may earn money if you buy.
2South Dakota Registered Agent.co$199$99/yr$397Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
3SD Registered Agent.org$199$99/yr$397Visit SD Registered Agent.orgPartner link. We may earn money if you buy.
Prices come from each company's own site, read November 13, 2026. Each row still needs South Dakota's $750 registration fee.

The assignments

  1. Assignment
    1

    Does the rule apply to you?

    When an LLC from elsewhere starts operating in South Dakota, foreign registration is the way in. Ignore the rule and this follows: Its contracts can still be enforced (SDCL 47-34A-1008(b)).

    Textbook page: Check the textbook page: sdlegislature.gov (read October 2026)

  2. Assignment
    2

    Ask your home state for proof of good standing

    Your filing must include certificate of Existence.

    Ask for the certificate shortly before filing day.

  3. Assignment
    3

    Appoint the 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.

    Any of the graded services can fill this seat.

    Textbook page: Check the textbook page: sdlegislature.gov (read October 2026)

  4. Assignment
    4

    Put together and mail the Application for Certificate of Authority, Foreign Limited Liability Company

    To register, hand the Application for Certificate of Authority, Foreign Limited Liability Company to the South Dakota Secretary of State with $750.

    Textbook page: Check the textbook page: sdsos.gov (read October 2026)

  5. Assignment
    5

    Look ahead to the recurring filing

    File the annual report at $55, 1st of the anniversary month to keep the registration going.

The bill

Line itemReceiverTotal
Registering the LLCState office$750
Annual reportState office$55
Optional serviceYour service$199 at the start
State total across three yearsState office$860
Rows for the state use South Dakota's published fee schedules (see the textbook pages beneath the table), and each service row uses that company's own price. Over three years the state row adds the filing, the year-two report, the year-three report and any minimum tax.

How the grades came out

pulled ahead of on homework the price does, which counts for 34%.

Your LLC was formed in one state and works in another, so a provider that serves both earned the best grade.

South Dakota pop quiz

What is South Dakota's fee for an out-of-state LLC?

$750 at the state office. Put $199 on top if you hire a service.

Which form do I file to register?

The South Dakota Secretary of State takes this form from foreign LLCs.

Do I need a certificate from my home state?

Yes: certificate of Existence.

What if the LLC does business there without registering?

Its contracts can still be enforced (SDCL 47-34A-1008(b)).

What is due after registering?

Assignment 5 has it: the annual report for $55.

Which service should handle the registration?

Mainstay Filing, because $199 on top of the state fee in any state, with year one of the agent included. Behind it come South Dakota Registered Agent.co and SD Registered Agent.org.

Next class

Textbook pages and extra reading

  1. If you want proof of the South Dakota Secretary of State, Business Services / facts, sdsos.gov is the page to read, and we last read it in August 2026.
  2. If you want proof of the South Dakota Secretary of State, Business Services / facts, sosenterprise.sd.gov is the page to read, and we last read it in August 2026.
  3. If you want proof of the South Dakota yearly filing: Annual report: fee and facts, sdlegislature.gov is the page to read, and we last read it in October 2026.
  4. If you want proof of the South Dakota report due date facts, sdlegislature.gov is the page to read, and we last read it in August 2026.
  5. If you want proof of the SDCL 47-34A-203 facts, sdlegislature.gov is the page to read, and we last read it in August 2026.
  6. If you want proof of the South Dakota formation fee: Filing fee, official source facts, sdsos.gov is the page to read, and we last read it in October 2026.
  7. If you want proof of the South Dakota formation fee: Filing fee, official source facts, sdlegislature.gov is the page to read, and we last read it in October 2026.
  8. If you want proof of the South Dakota registered agent statute facts, sdlegislature.gov is the page to read, and we last read it in October 2026.
  9. If you want proof of the South Dakota Secretary of State, business services facts, sdsos.gov is the page to read, and we last read it in October 2026.
  10. If you want proof of the Foreign LLC application for Certificate of Authority facts, sdsos.gov is the page to read, and we last read it in October 2026.
  11. If you want proof of the SDCL 47-34A-1003, transacting business facts, sdlegislature.gov is the page to read, and we last read it in October 2026.
  12. If you want proof of the SDCL 47-34A-1008, effect of not registering facts, sdlegislature.gov is the page to read, and we last read it in October 2026.
  13. If you want proof of the SDCL 47-34A-1001 to 47-34A-1009, foreign limited liability companies facts, sdlegislature.gov is the page to read, and we last read it in November 2026.
  14. Tuition figures from Mainstay Filing (South Dakota service page), November 13, 2026
  15. Tuition figures from South Dakota Registered Agent.co (pricing page), November 13, 2026
  16. Tuition figures from SD Registered Agent.org (pricing page), November 13, 2026