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The Formation Desk

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

Registered agent picks · South Dakota

3 Best Registered Agents in South Dakota (2026)

The The Formation Desk call for registered agents in South Dakota in 2026: Mainstay Filing ($149 a year), South Dakota Registered Agent.co ($99 a year) and SD Registered Agent.org ($99 a year), in that order. Mainstay Filing takes the call: $149 for a single agent plan that works in every state, $149 on renewal.
Written by The Formation Desk editorial team
1
Our top pick

1. Mainstay Filing: best for every state

$149 a year, and it holds on renewal

Editorial score 9.1 out of 10

The desk picks Mainstay Filing: $149 a year for an agent that goes wherever the company does, plus the first three government mailings each year scanned free.

Haven't formed yet? Mainstay's $199-a-year package handles the South Dakota filing and the annual report.

Over three years Mainstay runs $150 more than South Dakota Registered Agent.co, and the desk thinks the wider coverage is worth it.

In the price

  • An in-state street address on the public record
  • Same-business-day upload of scanned service of process, no fee
  • Your first three government mailings each year, scanned free
  • Compliance reminders

Strengths

  • $149 a year and it holds on renewal
  • First three government mailings each year, scanned free
  • Works for LLCs, corporations, LPs, LLPs and nonprofits alike
  • Free scans of served papers on the same business day

Cons

  • $50 a year more than South Dakota Registered Agent.co for agent service alone
  • Only the formation package files annual reports
Visit Mainstay FilingPartner link. We may earn money if you buy. Mainstay Filing up close
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Best for a South Dakota-only company

2. South Dakota Registered Agent.co: best for the lowest price per year on this list

$99 a year, and it holds on renewal

Editorial score 8.8 out of 10

Runner-up, South Dakota Registered Agent.co: a South Dakota specialist at $99 a year, with an in-state street address as the registered office.

Your registered office is an in-state street address from South Dakota Registered Agent.co, and legal papers served on the company are scanned for you.

In the price

  • A physical address in the state, as the registered office
  • Papers served on the company arrive in your account as scans

Strengths

  • Forms LLCs too, with the first agent year free
  • Comes in under Mainstay Filing every year
  • $99 yearly, renewing at the same price

Cons

  • The annual report is your job
  • South Dakota only; you need another agent elsewhere
Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy. South Dakota Registered Agent.co up close
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South Dakota only

3. SD Registered Agent.org: best for South Dakota companies

$99 a year, and it holds on renewal

Editorial score 8.6 out of 10

Third, SD Registered Agent.org: a South Dakota specialist at $99 a year, with an in-state street address as the registered office.

SD Registered Agent.org takes the registered office role, using an in-state address and scanning what is served there.

The published prices and features do not separate South Dakota Registered Agent.co from SD Registered Agent.org; take whichever you like.

In the price

  • An in-state street address for the registered office
  • Scanned copies of served legal papers, online

Strengths

  • Also forms LLCs and includes the first agent year
  • Costs $99 a year, the same each year
  • Yearly price below Mainstay Filing's

Cons

  • The annual report is your job
  • South Dakota only; you need another agent elsewhere
Visit SD Registered Agent.orgPartner link. We may earn money if you buy. SD Registered Agent.org up close

The desk's 3 picks in brief

Pick Service Desk score Price a year Renewal Good for Visit
1 Mainstay Filing 9.1 $149 $149/yr One agent that covers every state Visit Mainstay FilingPartner link. We may earn money if you buy.
2 South Dakota Registered Agent.co 8.8 $99 $99/yr The lowest yearly price we rank here Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
3 SD Registered Agent.org 8.6 $99 $99/yr The lowest yearly price we rank here Visit SD Registered Agent.orgPartner link. We may earn money if you buy.

A score out of 10 here is editorial judgment built on the criteria explained on How we rank, not an average of customer ratings.

What a South Dakota registered agent costs in 2026: year one, renewal and the three-year bill

Service Year one Year two Year three Bill over three years Price holds on renewal
Mainstay Filing $149 $149 $149 $447 Yes
South Dakota Registered Agent.co $99 $99 $99 $297 Yes
SD Registered Agent.org $99 $99 $99 $297 Yes

Every price here was read off the company's own pages on November 12, 2026. South Dakota charges the same state fees whichever agent you name.

What tipped the order

Here is the weighting: 33% for spend over three years, 33% for work the price removes, 34% spread over what renewal looks like, fit with the state and plain price display. In South Dakota, work the price removes made the call.

Mainstay's agent plan brings more to the table: served papers are scanned the same business day for nothing, one price in all fifty states and three government mailings a year scanned free. South Dakota Registered Agent.co is cheaper, and it was close.

The full criteria and weights are on How we rank.

South Dakota registered agent rules straight from 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. The law behind it: SDCL 59-11-6.

South Dakota's annual report: what it costs, when it is due, who gets the notice

South Dakota LLCs send in the annual report every year, due due during the entity's anniversary month. The state's fee is $55. Send it late and $50 gets added. Notices about it land with your registered agent.

South Dakota registered agent: reader questions

Do you need a registered agent to run a South Dakota LLC?

You do. South Dakota wants a registered agent on file for every LLC, and the agent must have a street address in the state.

What should you expect to pay a South Dakota registered agent?

Plan on $99 to $149 a year, and the price holds when it renews.

Could you serve as your own registered agent?

You can if the state's rules allow it. 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.

When does the South Dakota annual report have to go in?

Get it in by due during the entity's anniversary month. The state's cut is $55. Miss the date and it costs $50 more.

Which registered agents did the desk rank here?

Mainstay Filing ($149 a year), South Dakota Registered Agent.co ($99 a year) and SD Registered Agent.org ($99 a year), best pick first.

Who is our pick for registered agent in South Dakota?

Mainstay Filing, since $149 a year, and it holds on renewal, with papers served on the company scanned the same business day for free.

See also

Where the numbers came from

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