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Researched and written by the Launchwise Review editorial team
Launchwise Review

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

Launch guide · South Dakota · registered agent

3 Best Registered Agents in South Dakota (2026)

Researched and written by the Launchwise Review editorial team
For a 2026 launch in South Dakota, Launchwise Review grades registered agents this way: Mainstay Filing ($149 a year), SD Registered Agent.org ($99 a year) and South Dakota Registered Agent.co ($99 a year). Mainstay Filing earns the top grade here: the price stays $149 a year if you stay put or expand, and your first three government letters each year are scanned free.
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Number one here

1. Mainstay Filing: best for all fifty states

$149 a year, flat

Our mark 9.1 out of 10

Top grade, Mainstay Filing: $149 a year, still $149 at renewal, and papers served on the company are scanned the same business day at no charge.

Launching a new company? The $199 yearly package also takes care of the South Dakota filing and the annual report.

It runs $150 above SD Registered Agent.org across three years; the extra paperwork it handles is worth that to us.

In the price

  • A registered office street address in any state you need
  • Same-business-day scans of legal papers served on the company, free
  • Your first three government letters each year, scanned free
  • Compliance reminders

Pros

  • Your first three government letters each year are scanned free
  • Works for LLCs, corporations, LPs, LLPs and nonprofits
  • $149 a year and it does not rise
  • Papers served on the company are scanned the same business day, free

Less good

  • The agent plan alone costs $50 a year more than SD Registered Agent.org
  • Report filing belongs to the formation package, not the agent plan
Visit Mainstay FilingPartner link. We may earn money if you buy.
Read the Mainstay Filing launch review
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Best for a South Dakota-only company

2. SD Registered Agent.org: best for the smallest annual bill we rank here

$99 a year, flat

Our mark 8.6 out of 10

Next up is SD Registered Agent.org: a South Dakota specialist at $99 a year, supplying an in-state street address for the registered office.

SD Registered Agent.org puts its in-state street address on file as the company's registered office and scans served legal papers to you.

In the price

  • The in-state address the state asks for
  • Papers served on the company are scanned and sent to your account

Pros

  • LLC formation with year-one agent service included
  • Costs less per year than Mainstay Filing
  • You pay $99 a year, renewals included

Less good

  • You still file the annual report
  • Made for South Dakota; other states need their own agent
Visit SD Registered Agent.orgPartner link. We may earn money if you buy.
Read the SD Registered Agent.org launch review
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Built for South Dakota

3. South Dakota Registered Agent.co: best for South Dakota specialists

$99 a year, flat

Our mark 8.3 out of 10

Rounding out the list is South Dakota Registered Agent.co: a South Dakota specialist at $99 a year, supplying an in-state street address for the registered office.

Your registered office becomes South Dakota Registered Agent.co's street address in the state, and you read anything served on the company as a scan online.

Nothing in the published price or features separates SD Registered Agent.org from South Dakota Registered Agent.co; go with whichever you like.

In the price

  • A state street address on file as the registered office
  • You get scans of served legal papers online

Pros

  • Forms LLCs too, with a free first agent year
  • Mainstay Filing charges more each year
  • $99 yearly, held steady at renewal

Less good

  • You still file the annual report
  • Made for South Dakota; other states need their own agent
Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
Read the South Dakota Registered Agent.co launch review

The 3 grades at a glance

Place Company Launch grade Per year At renewal Best fit Go
1 Mainstay Filing 9.1 $149 $149/yr An agent for every state you may enter Visit Mainstay FilingPartner link. We may earn money if you buy.
2 SD Registered Agent.org 8.6 $99 $99/yr The lowest yearly price among the picks we rank here Visit SD Registered Agent.orgPartner link. We may earn money if you buy.
3 South Dakota Registered Agent.co 8.3 $99 $99/yr The lowest yearly price among the picks we rank here Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy.
Each grade out of 10 reflects our editors' reading of the weighted criteria on How we rank, not a customer rating.

South Dakota registered agent cost in 2026: first year, renewals, three-year total

Company Year 1 Year 2 Year 3 Three years, total Renewal price matches
Mainstay Filing $149 $149 $149 $447 Yes
SD Registered Agent.org $99 $99 $99 $297 Yes
South Dakota Registered Agent.co $99 $99 $99 $297 Yes
Prices were copied from each company's own pages on November 12, 2026. South Dakota's own fees do not change with your choice of agent.

Why Mainstay Filing grades first

Launchwise Review puts 26% on cost to launch and stay and 26% on launch paperwork handled, then spreads 48% over renewal behavior, state match and price transparency. For South Dakota, the call came down to launch paperwork handled.

Mainstay's plan covers more ground: papers served on the company are scanned the same business day at no charge, the price is the same in all fifty states, and three government letters a year are scanned free. SD Registered Agent.org costs less, and the grades are close.

Every criterion and weight is listed on How we rank.

South Dakota registered agent rules, straight from South Dakota Secretary of State

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. Law behind it: SDCL 59-11-6.

South Dakota annual report: date and fee

Put the annual report on your South Dakota calendar every year. Count on a $55 state charge, with the deadline at due during the entity's anniversary month. Miss it and $50 gets added. Your registered agent receives the state's notices about it.

Quick answers about South Dakota registered agents

Do I have to line up a registered agent before launching a South Dakota LLC?

Yes. Put a registered agent with a physical South Dakota address on the paperwork, because the state will not accept an LLC without one.

What should I budget each year for a South Dakota registered agent?

Expect $99 to $149 a year, and each company keeps its price at renewal.

Could I just serve as my own registered agent?

Often yes, if you meet the state's conditions. 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 come due?

Put due during the entity's anniversary month on your calendar. The state asks $55, and a late filing adds $50.

Which registered agents are graded on this page?

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

Which South Dakota registered agent should a new company pick first?

Mainstay Filing, because one agent plan at $149 a year that works in every state, renewing at $149.

Read next

Sources and dates

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