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LLC UnpackedEvery filing, unpacked: the fee, the form, the catch.

Unpacked · South Dakota

3 Best Registered Agents in South Dakota (2026), Opened Up

In South Dakota for 2026, unpack registered agents in this order: Mainstay Filing ($149 a year), South Dakota Registered Agent.co ($99 a year) and SD Registered Agent.org ($99 a year). An agent opens at $99 to $149 in the first year and totals $297 to $447 by year three.
Unpacked by the LLC Unpacked editorial team

Top layer

Must the LLC name an agent?
Required, yes
What the law calls it
Registered agent
What agents charge
$99 to $149 a year
Our pick
Mainstay Filing, South Dakota Registered Agent.co then SD Registered Agent.org

The South Dakota stack, best on top

Curious about the order? The method is here.
Ranked first

1. Mainstay Filing: best for an LLC that may expand

$149 a year, then $149 at renewal

Mainstay Filing sits on top in South Dakota because its price is $149 a year here and identical in every other state.

South Dakota Registered Agent.co would save $150 across three years if the LLC stays in South Dakota.

Inside the price

  • A street address inside the state
  • Scans of three government mailings a year at no charge
  • Reaches beyond LLCs: corporations, LPs, LLPs and nonprofits

Inside, the good

  • $149 each year, no increase
  • One price in all fifty states

Inside, the catch

  • $50 a year more than South Dakota Registered Agent.co
  • Agent role only, no report filing
South Dakota only

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

$99 a year, then $99 at renewal

What puts South Dakota Registered Agent.co second: three years for a South Dakota-only company come to $297.

Inside the price

  • A local address on file
  • Scans of legal papers online

Inside, the good

  • Below Mainstay Filing on yearly price
  • $99 a year, flat at renewal

Inside, the catch

  • South Dakota only
  • The annual report sits outside the box
South Dakota only

3. SD Registered Agent.org: best for keeping the agent local

$99 a year, then $99 at renewal

What puts SD Registered Agent.org third: three years for a South Dakota-only company come to $297.

It charges what South Dakota Registered Agent.co charges.

Inside the price

  • A local address on file
  • Scans of legal papers online

Inside, the good

  • Below Mainstay Filing on yearly price
  • $99 a year, flat at renewal

Inside, the catch

  • South Dakota only
  • The annual report sits outside the box

Inside each price

#CompanyYear oneRenewalThree-year totalCovers
1Mainstay Filing$149$149/yr$447A street address inside the state; scans of three government mailings a year at no charge; Reaches beyond LLCs: corporations, LPs, LLPs and nonprofitsSee Mainstay FilingPartner link. We may earn money if you buy.
2South Dakota Registered Agent.co$99$99/yr$297A local address on file; scans of legal papers onlineSee South Dakota Registered Agent.coPartner link. We may earn money if you buy.
3SD Registered Agent.org$99$99/yr$297A local address on file; scans of legal papers onlineSee SD Registered Agent.orgPartner link. We may earn money if you buy.
Prices as of November 13, 2026. The state's own fees are in the checklist below.

Layer by layer

Must the LLC name a registered agent?

Every LLC must name a registered agent with an in-state street address.

The law underneath: SDCL 59-11-6. peek at sdlegislature.gov, confirmed October 2026

Who is allowed to be the agent?

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.

If you qualify, you can serve yourself at no cost.

How much does an agent cost?

A year of agent service runs $99 to $149 with our picks, and three years run $297 to $447.

No state fee depends on the agent you name.

Why does the state want an agent?

Court papers and state notices for the company land at the agent's South Dakota address first.

What matters is that nothing important sits unnoticed while you are away. What is service of process?

Is anything else due every year?

Underneath it all, one filing repeats: the annual report, every year, at $55 each time. The state phrases its deadline like this: due during the entity's anniversary month.

peek at sdlegislature.gov, confirmed October 2026

Why is the stack in this order?

Mainstay Filing is strongest on what is inside the price, a layer worth 29% of the score.

Two layers carry most of the weight, total across three years (34%) and what is inside the price (29%).

Add a state later and the same agent and price come along, while South Dakota Registered Agent.co ends at the South Dakota line.

The five layers

What South Dakota requires of an agent

PartAmount or rulePeek at source
Fee to form$150peek at sdlegislature.gov, confirmed October 2026
Registered agentRequired, yespeek at sdlegislature.gov, confirmed October 2026
Annual report$55 every yearpeek at sdlegislature.gov, confirmed October 2026
What the state collects in three years$260Our total of the rows above
To check the total yourself, add the filing fee, the next two reports and any minimum tax. Costs without a set amount are left out.

Also worth asking

May an owner serve as agent?

Yes, when your address and status match the rule. Many owners still hire a service to keep an address private.

Which addresses does the state accept?

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.

How do the three-year totals compare?

Mainstay Filing stacks up to $447, South Dakota Registered Agent.co stacks up to $297, SD Registered Agent.org stacks up to $297

What do these numbers rest on?

Two kinds of source feed this page: South Dakota's official documents for what the state charges, and company price pages for what services charge.

Does the law require one?

No. Owners can file with the state directly. A service saves time and can act as agent, but nothing makes you hire one.

What is the best registered agent for South Dakota?

Mainstay Filing, because nothing inside changes by state: $149 a year, $149 at renewal. Then South Dakota Registered Agent.co and SD Registered Agent.org.

Originals behind this page

  1. Unpacking South Dakota Secretary of State led us to sdsos.gov, confirmed August 2026, which you can open yourself
  2. Unpacking South Dakota Secretary of State led us to sosenterprise.sd.gov, confirmed August 2026, which you can open yourself
  3. Unpacking South Dakota yearly filing: Annual led us to sdlegislature.gov, confirmed October 2026, which you can open yourself
  4. Unpacking South Dakota report due date led us to sdlegislature.gov, confirmed August 2026, which you can open yourself
  5. Unpacking SDCL 47-34A-203 led us to sdlegislature.gov, confirmed August 2026, which you can open yourself
  6. Unpacking South Dakota formation fee: Filing led us to sdsos.gov, confirmed October 2026, which you can open yourself
  7. Unpacking South Dakota formation fee: Filing led us to sdlegislature.gov, confirmed October 2026, which you can open yourself
  8. Unpacking South Dakota registered agent statute led us to sdlegislature.gov, confirmed October 2026, which you can open yourself
  9. Mainstay Filing South Dakota service page, read November 13, 2026
  10. South Dakota Registered Agent.co pricing page, read November 13, 2026
  11. SD Registered Agent.org pricing page, read November 13, 2026