1099 Contractor in Colorado with a South Dakota Client: Where Do You File?
Answer
One state, paid quarterly. Your services are performed in Colorado, which makes the income Colorado-source and Colorado-taxed; South Dakota taxes no personal income at all. Set aside for Colorado estimated payments — no client withholds anything for you.
Last verified
Nothing is withheld from a 1099, so the tax that a W-2 employee never sees is money you are holding on someone else's behalf. In this pairing all of it belongs to Colorado, and none of it to South Dakota.
What you file
- 1Quarterly estimated payments · Colorado
Make quarterly estimated payments to Colorado Department of Revenue — Taxation Division — nothing is withheld from a 1099.
- 2Resident return · Colorado
File a Colorado resident return reporting your full self-employment income.
The two states, side by side
| Colorado | South Dakota | |
|---|---|---|
| Taxes wages | Yes — flat | No |
| Reciprocity partners | None | None |
| Convenience rule | No | No |
| Nonresident return | Form DR 0104 with Schedule DR 0104PN | Not applicable |
| Credit for other-state tax | Form DR 0104CR | No income tax |
| Nonresident safe harbour | None published | Not applicable |
| Local income tax | Yes | No |
| Revenue department | Colorado Department of Revenue — Taxation Division | South Dakota Department of Revenue |
| Last verified |
The other direction
Reversing the commute does not always reverse the answer. Living in South Dakota and working in Colorado gives:Client state only, if you work there.
Same two states, different situation
The withholding answer turns on how you are paid and where the work happens, not only on which two states are involved.
- W-2 commuter: Colorado → South DakotaHome state only
- Remote worker: Colorado → South DakotaHome state only
- Moved mid-year: Colorado → South DakotaOne part-year return — the state you left
Other Colorado pairs
Questions people actually ask
I live in Colorado and my client is in South Dakota. Do I have to file a South Dakota tax return?
One state, paid quarterly. Your services are performed in Colorado, which makes the income Colorado-source and Colorado-taxed; South Dakota taxes no personal income at all. Set aside for Colorado estimated payments — no client withholds anything for you.
Do reciprocity agreements help a 1099 contractor?
No. Every state reciprocity agreement in the country is an arrangement about wage withholding between two revenue departments, and a 1099 has no withholding to switch off. Whether Colorado and South Dakota hold an agreement makes no difference to a self-employed filer — sourcing rules decide the answer instead.
How current is this?
The Colorado and South Dakota rules on this page were last checked against Colorado Department of Revenue — Taxation Division and South Dakota Department of Revenue on 2026-08-07. We re-check the full grid every December after state legislative sessions close, and re-check the convenience-of-the-employer states quarterly because that is where the rules move fastest.
Sources
Every fact above comes from the revenue department that publishes the rule. We do not cite secondary summaries, and we do not restate a figure we could not find at source.
- Colorado Department of Revenue — Taxation Division — individual income taxaccessed 2026-08-07
- South Dakota Department of Revenue — individual income taxaccessed 2026-08-07