LLC Review Desk's 2026 picks for registered agents in South Dakota, favorite first, are SD Registered Agent.org ($99 a year), Mainstay Filing ($149 a year) and South Dakota Registered Agent.co ($99 a year). SD Registered Agent.org is our favorite, because it's $99 a year, and the price stays put at renewal, the smallest yearly price among these picks.
By the LLC Review Desk editorial team
Position 1
Our top pick in South Dakota
1. SD Registered Agent.org: best for the smallest yearly price on this list
$99 a year, the same each year
Our score
9.4out of 10
9.4 out of 10
Our favorite is SD Registered Agent.org, because it focuses on South Dakota at $99 a year and gives you an in-state street address for the registered office.
SD Registered Agent.org lists its own in-state street address as your company's registered office and scans served legal papers for you.
Over three years it costs less than Mainstay Filing, and cost is one of our two biggest criteria.
In the price
A state street address listed as your registered office
You open served legal papers online as scans
What we like
Costs less a year than Mainstay Filing
LLC formation with year-one agent service included
You pay $99 a year, renewals included
Trade-offs
The annual report is a job that stays with you
Built for South Dakota; other states need another agent
3. South Dakota Registered Agent.co: best for South Dakota specialists
$99 a year, the same each year
Our score
8.9out of 10
8.9 out of 10
In third place is South Dakota Registered Agent.co, because it focuses on South Dakota at $99 a year and gives you an in-state street address for the registered office.
The registered office you get is South Dakota Registered Agent.co's address inside the state, and you read whatever is served on the company as a scan online.
Price and features don't set SD Registered Agent.org apart from South Dakota Registered Agent.co; pick the one you like.
In the price
The in-state street address the state requires
Anything served on the company is scanned for you to open online
What we like
Mainstay Filing charges more each year
$99 yearly, no change at renewal
Forms LLCs too, and the first agent year is free
Trade-offs
The annual report is a job that stays with you
Built for South Dakota; other states need another agent
Every score out of 10 is our editors' call, made with the weighted criteria on How we rank, not a customer rating.
What South Dakota registered agents cost in 2026: year one, renewals and three years
Service
First year
Second year
Third year
Three-year total
Same price when you renew
SD Registered Agent.org
$99
$99
$99
$297
Yes
Mainstay Filing
$149
$149
$149
$447
Yes
South Dakota Registered Agent.co
$99
$99
$99
$297
Yes
We took each price from the company's own pages on November 12, 2026. South Dakota's own fees stay the same no matter which agent you choose.
Why we put SD Registered Agent.org first
LLC Review Desk gives three-year cost 29% and filings in the price 29%, then divides 42% among renewal price, state fit and up-front totals. For South Dakota, it came down to three-year cost.
SD Registered Agent.org comes to $297 over three years, which is $150 less than Mainstay Filing. If you only need an agent in South Dakota, fifty-state reach doesn't help much, so the lower yearly price won.
You can read every criterion and weight on How we rank.
What South Dakota says about the registered agent (via 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. The law: SDCL 59-11-6.
The South Dakota annual report: when and how much
Here's the schedule: the annual report is due every year in South Dakota, by due during the entity's anniversary month. It costs $55. If you're late, add $50. Reminders from the state go to your registered agent.
Your questions about South Dakota registered agents
Do I really need a registered agent for a South Dakota LLC?
You do. South Dakota won't accept an LLC without a registered agent who has a street address in the state, and that name goes on the public record.
What do South Dakota registered agents usually cost per year?
Plan on $99 to $149 a year, and each service keeps its price when you renew.
Can I be my own registered agent?
Sometimes, if you meet the state's rules. 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 do I have to send in the South Dakota annual report?
Mark due during the entity's anniversary month on your calendar. The state's charge is $55, and sending it late tacks on $50.
Which registered agents did we review here?
SD Registered Agent.org ($99 a year), Mainstay Filing ($149 a year) and South Dakota Registered Agent.co ($99 a year), with our favorite first.
Who is the best registered agent for South Dakota?
SD Registered Agent.org, because you pay a flat $99 a year, and papers served on the company are scanned into your account.