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Biz Formation Report

Rankings of registered agents, LLC formation and foreign registration services in all 50 states.

Registered agents report · South Dakota

3 Best Registered Agents in South Dakota (2026)

By the Biz Formation Report editorial team

Biz Formation Report ranks registered agents in South Dakota for 2026 as Mainstay Filing ($149 a year), SD Registered Agent.org ($99 a year) and South Dakota Registered Agent.co ($99 a year), in that order. Mainstay Filing earns the top grade: a $149 yearly plan that works in every state, renewing at $149.

No.1

Our top pick in South Dakota

1. Mainstay Filing: best for all fifty states

Score9.4out of 10
$149 a year, unchanged at renewal

Top grade, Mainstay Filing: $149 per year for an agent that goes wherever the company goes, plus free scans of the first three government mailings each year.

A company still to be formed can use Mainstay's $199-a-year package, which files the South Dakota paperwork and the annual report.

Over three years Mainstay costs $150 more than SD Registered Agent.org; our grading treats the broader coverage as worth that.

What you get

  • A physical address in the state on the public record
  • Service of process scanned and uploaded within one business day, free
  • Scans of the first three government mailings each year, free
  • Compliance reminders

Good

  • Served papers scanned within the same business day, free
  • $149 a year, no renewal increase
  • Three government mailings a year scanned at no cost
  • Open to LLCs, corporations, LPs, LLPs and nonprofits

Weak spots

  • The agent alone costs $50 a year more than SD Registered Agent.org
  • You file annual reports yourself on the agent plan
Visit Mainstay FilingPartner link. We may earn money if you buy.
Read the Mainstay Filing review
No.2

Best local option

2. SD Registered Agent.org: best for the lowest annual price on this list

Score9.0out of 10
$99 a year, unchanged at renewal

Second grade, SD Registered Agent.org: $99 a year flat, with online scans of any legal papers served.

With SD Registered Agent.org, the registered office has a street address in the state, and served papers reach you as online scans.

What you get

  • The state street address required for the registered office
  • Papers served on the company are scanned and delivered to your account

Good

  • Also forms LLCs and includes the first agent year
  • A flat $99 per year
  • Costs less per year than Mainstay Filing

Weak spots

  • The annual report filing is left to you
  • Serves South Dakota only; other states need a separate agent
Visit SD Registered Agent.orgPartner link. We may earn money if you buy.
Read the SD Registered Agent.org review
No.3

Built for South Dakota

3. South Dakota Registered Agent.co: best for companies based in South Dakota

Score8.8out of 10
$99 a year, unchanged at renewal

Third grade, South Dakota Registered Agent.co: $99 a year flat, with online scans of any legal papers served.

The company's registered office is an in-state street address supplied by South Dakota Registered Agent.co; scans of served legal papers appear in your account.

Prices and features do not separate SD Registered Agent.org from South Dakota Registered Agent.co; either works.

What you get

  • A physical in-state address listed for the company
  • Online scans of legal papers served on the company

Good

  • $99 annually with no renewal increase
  • Forms LLCs as well, with year-one agent service included
  • Beats Mainstay Filing on yearly cost

Weak spots

  • The annual report filing is left to you
  • Serves South Dakota only; other states need a separate agent
Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
Read the South Dakota Registered Agent.co review

Summary of the 3 grades

RankProviderGradePrice per yearRenewal priceBest fitSite
1Mainstay Filing9.4$149$149/yrOne agent across fifty statesVisit Mainstay FilingPartner link. We may earn money if you buy.
2SD Registered Agent.org9.0$99$99/yrThe lowest yearly price we rank hereVisit SD Registered Agent.orgPartner link. We may earn money if you buy.
3South Dakota Registered Agent.co8.8$99$99/yrThe lowest yearly price we rank hereVisit South Dakota Registered Agent.coPartner link. We may earn money if you buy.

The grades are editorial: Biz Formation Report assigns every mark out of 10 using the criteria on How we rank, not customer ratings.

South Dakota registered agent prices, 2026: year one, renewal and three-year outlay

ProviderYear 1Year 2Year 3Three-year outlayRenewal at the same price
Mainstay Filing$149$149$149$447Yes
SD Registered Agent.org$99$99$99$297Yes
South Dakota Registered Agent.co$99$99$99$297Yes

All prices were taken from the companies' own websites on November 12, 2026. South Dakota's own fees are the same whichever agent is named.

Why Mainstay Filing ranks first

Of the grade, 32% rests on three-year bill and 32% on what the money buys; renewal handling, local rules match and pricing openness share the remaining 36%. What the money buys decided South Dakota.

Mainstay's agent plan grades higher on coverage: served papers are scanned the same business day at no fee, the price is identical in all fifty states and three government mailings a year are scanned free. SD Registered Agent.org wins on cost, and the margin is thin.

Every criterion and weight is listed on How we rank.

South Dakota registered agent rules according to South Dakota Secretary of State (official)

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. Authority: SDCL 59-11-6.

South Dakota's annual report: cost, deadline and your agent

The annual report is due from every South Dakota LLC every year, by due during the entity's anniversary month. The state charges $55. A late filing adds $50. Related notices are mailed to your registered agent.

South Dakota registered agent: common questions

Does a South Dakota LLC have to maintain a registered agent?

Yes. The state expects every LLC to keep a registered agent on record, and South Dakota requires that agent to have a street address inside its borders.

How much do South Dakota registered agents charge per year?

Annual charges run from $99 to $149, and prices are unchanged at renewal.

Can the owner be the company's own registered agent?

Yes, provided you meet the state's requirements. A commercial registered agent listed with the state, a noncommercial agent (an individual or entity with a South Dakota address), or the title of an office in the company.

What is the filing deadline for the South Dakota annual report?

The deadline: due during the entity's anniversary month. The state charges $55. Miss it and $50 is added.

Which registered agents does this report rank?

Mainstay Filing ($149 a year), SD Registered Agent.org ($99 a year) and South Dakota Registered Agent.co ($99 a year), in descending order of grade.

What is the best-value registered agent in South Dakota?

Mainstay Filing: $149 a year, flat at renewal, with papers served on the company scanned the same business day at no charge.

More from us

Source notes

  1. South Dakota Secretary of State, Business Services / Corporations Division (verified August 2026)
  2. South Dakota Secretary of State, Business Services / Corporations Division (verified August 2026)
  3. South Dakota yearly filing: Annual report: fee and how, official source (verified October 2026)
  4. South Dakota report due date (verified August 2026)
  5. SDCL 47-34A-203 (verified August 2026)
  6. South Dakota formation fee: Filing fee, official source (verified October 2026)
  7. South Dakota formation fee: Filing fee, official source (verified October 2026)
  8. South Dakota registered agent statute (verified October 2026)
  9. Pulled November 12, 2026: Mainstay Filing, South Dakota service page
  10. Pulled November 12, 2026: SD Registered Agent.org, pricing and service pages
  11. Pulled November 12, 2026: South Dakota Registered Agent.co, pricing and service pages