Place1
Number one hereSD Registered Agent.org
1. SD Registered Agent.org: best for a low yearly agent cost
$199 plus the state fee; agent $99 a year from year two
Our mark9.3out of 10
SD Registered Agent.org earns first place with $199 plus the state fee with a year of registered agent service included, then $99 a year for the agent.
It provides the in-state registered office address and posts scans of served legal papers online.
On our method the lower three-year cost outweighs what Mainstay adds to its price.
What you get
- South Dakota registration filed for you
- A year of registered agent service
Why pick it
- $99 yearly from year two
- $199 plus the state's fee
- A year of registered agent service included
Less good
- No help outside South Dakota
- EIN application is a $99 add-on
Place2
Fifty-state coverageMainstay Filing
2. Mainstay Filing: best for one price in every state
$199 plus the state fee ($949 due today); agent $149 a year from year two
Our mark8.8out of 10
Mainstay Filing comes second with it prepares and files the South Dakota registration for $199 and names itself your registered agent, free for year one.
The agent renews at $149, the same price wherever the company registers.
The extra $100 over three years is the reason it trails SD Registered Agent.org on our cost score.
What you get
- Registration prepared and filed
- Your registered agent, free for the first year
- Service of process scanned the same business day, no fee
Why pick it
- Registered agent free for the first year
- Service of process scanned the same business day, no fee
- $199 service fee
- Any state, same fee
Less good
- Renewal costs $50 more than SD Registered Agent.org
Place3
Lower renewal than MainstaySouth Dakota Registered Agent.co
3. South Dakota Registered Agent.co: best for South Dakota registrations
$199 plus the state fee; agent $99 a year from year two
Our mark8.6out of 10
Number 3 is South Dakota Registered Agent.co: $199 plus the state fee with a year of registered agent service included, then $99 a year for the agent.
It provides the in-state registered office address and posts scans of served legal papers online.
SD Registered Agent.org and South Dakota Registered Agent.co publish the same prices and the same plan features, so the gap between them is small and either is a sound choice.
What you get
- South Dakota registration filed for you
- A year of registered agent service
Why pick it
- $199 plus the state's fee
- A year of registered agent service included
- $99 yearly from year two
Less good
- No help outside South Dakota
- EIN application is a $99 add-on
Shortlist at a glance
| Rank | Service | Our score | Service fee | Year two | Best for | Link |
|---|
| 1 | SD Registered Agent.org | 9.3 | $199 | $99/yr | Lowest agent renewal on this list | Visit SD Registered Agent.orgPartner link. We may earn money if you buy. |
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| 2 | Mainstay Filing | 8.8 | $199 | $149/yr | Companies registered in several states | Visit Mainstay FilingPartner link. We may earn money if you buy. |
|---|
| 3 | South Dakota Registered Agent.co | 8.6 | $199 | $99/yr | Lowest agent renewal on this list | Visit South Dakota Registered Agent.coPartner link. We may earn money if you buy. |
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The Founders Review sets these scores itself from the five criteria on our method page; they are not user ratings.
South Dakota pricing for 2026: what each service costs
| Service | Year one | Year two | Year three | Three-year total | Agent in year one |
|---|
| SD Registered Agent.org | $199 | $99 | $99 | $397 | Included |
|---|
| Mainstay Filing | $199 | $149 | $149 | $497 | Free |
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| South Dakota Registered Agent.co | $199 | $99 | $99 | $397 | Included |
|---|
Read from each provider's pricing page on November 12, 2026. These totals leave out South Dakota's $750 registration fee.
How the order was decided
What split first and second in South Dakota: three-year cost, weighted at 30% in our method.
Three-year cost: $397 with SD Registered Agent.org, saving $100 against Mainstay Filing. Both include the first agent year, so the renewal price after that decided it.
See How we rank for every criterion and weight.
South Dakota foreign registration fee and form (official)
Out-of-state companies file the Application for Certificate of Authority, Foreign Limited Liability Company with the South Dakota Secretary of State; the state charges $750. South Dakota also wants certificate of Existence.
After registering, the company files the annual report ($55), due 1st of the anniversary month.
What to have ready
- Certificate of Existence.
- The company's exact legal name as it appears in its home state, plus its formation date.
- An in-state registered agent, which each ranked service provides.
- The $750 state fee, paid with the filing.
- A date in your calendar for the annual report and its $55 fee.
Risks of skipping registration
Its contracts stay valid (SDCL 47-34A-1008(b)).
Common South Dakota questions
Do I need to register my out-of-state LLC in South Dakota?
Yes, if the company transacts business there.
How much does foreign registration cost in South Dakota?
State fee $750, service fee $199.
Do I need a certificate from my home state?
Yes: certificate of Existence.
Do I need a registered agent after registering?
Yes. Every LLC must name a registered agent with an in-state street address.
Which foreign registration services do you rank here?
SD Registered Agent.org ($199), Mainstay Filing ($199) and South Dakota Registered Agent.co ($199), in this order.
Which foreign registration service is best in South Dakota?
On our method, SD Registered Agent.org: the South Dakota registration filed for $199, the first agent year included and $99 a year after.
Sources and dates
- South Dakota Secretary of State, Business Services / Corporations Division (checked August 2026): sdsos.gov/docs/business/llc-domestic-annualreport.pdf
- South Dakota Secretary of State, Business Services / Corporations Division (checked August 2026): sosenterprise.sd.gov/BusinessServices/Business/AnnualReportInstr.aspx
- South Dakota yearly filing: Annual report: fee and how, official source (checked October 2026): sdlegislature.gov/api/Statutes/59-11-24.html
- South Dakota report due date (checked August 2026): sdlegislature.gov/Statutes/47-34A-211
- SDCL 47-34A-203 (checked August 2026): sdlegislature.gov/Statutes/47-34A-212
- South Dakota formation fee: Filing fee, official source (checked October 2026): sdsos.gov/general-information/filing-fees.aspx
- South Dakota formation fee: Filing fee, official source (checked October 2026): sdlegislature.gov/api/Statutes/47-34A-212.html
- South Dakota registered agent statute (checked October 2026): sdlegislature.gov/Statutes/59-11-6
- South Dakota Secretary of State, business services (checked October 2026): sdsos.gov/business-services/corporations/contact.aspx
- Foreign LLC application for Certificate of Authority (checked October 2026): sdsos.gov/docs/business/foreignllccertificateofauthority20180215.pdf
- SDCL 47-34A-1003, transacting business (checked October 2026): sdlegislature.gov/api/Statutes/47-34A-1003.html
- SDCL 47-34A-1008, effect of not registering (checked October 2026): sdlegislature.gov/api/Statutes/47-34A-1008.html
- SDCL 47-34A-1001 to 47-34A-1009, foreign limited liability companies (checked November 2026): sdlegislature.gov/Statutes/47-34A-1002
- SD Registered Agent.org: pricing and service pages, read November 12, 2026
- Mainstay Filing: South Dakota service page, read November 12, 2026
- South Dakota Registered Agent.co: pricing and service pages, read November 12, 2026