Intermediate Quick Answer

What are the penalties for not collecting or remitting sales tax?

⚡ TL;DR

Penalties stack in three layers: a failure-to-register charge, per-period failure-to-file penalties of 10–25%, and interest at 0.5–1.5% per month from each period's original due date. On three years of non-compliance, total penalties and interest can add 30–55% on top of the underlying tax. A VDA eliminates the penalty layer.

The penalties for not collecting sales tax stack in three layers: the failure-to-register penalty, the per-period failure-to-file or failure-to-pay penalty, and interest on the unpaid balance. Each compounds over time. Here’s what the math actually looks like.

The three penalty layers

Layer 1: Failure-to-register penalty

Most states assess a one-time penalty when they discover a seller had nexus but never registered. This ranges from a flat fee ($50–$500 in some states) to a percentage of the total liability. Some states fold this into the per-period penalty structure rather than charging it separately.

Layer 2: Per-period failure-to-file and failure-to-pay penalties

For each filing period where a return was due and wasn’t filed (or tax was owed and wasn’t paid), states assess a penalty. Common structures:

Percentage of tax owed: Most common. Typically 5–10% for the first month late, stepping up to 15–25% for extended non-filing. Some states cap the total penalty per period; others don’t.
Flat per-period penalty: A few states charge a flat amount per unfiled period regardless of the tax owed, plus a percentage if the tax owed is significant.

For a seller with three years of uncollected monthly returns across a state with a 15% penalty rate, every period carries a 15% surcharge on that period’s tax liability. Across 36 periods of non-filing, that compounds significantly.

Layer 3: Interest on the unpaid balance

Interest is separate from penalties and is not typically waived by a VDA. States treat it as compensation for the time value of the money they should have received.

Common rates: 0.5% to 1.5% per month on the unpaid tax. That’s roughly 6% to 18% annually. Interest accrues from the original due date of each return, so on a return that was due 3 years ago and never filed, interest has been running for 36 months.

Example: $5,000 in unpaid tax for a period due three years ago, at 1% monthly interest = approximately $1,800 in interest alone on that single period. Multiply across 36 periods of a monthly filing state.

What the combined exposure looks like

A seller who hasn’t collected in a state for three years, with $200,000 in annual taxable revenue and a 6% effective tax rate:

Unpaid tax: ~$36,000 (3 years × $12,000/year)
Penalties (15% per period, monthly filing, 36 periods): ~$5,400
Interest (1%/month accruing from each period’s due date): ~$9,000–15,000 depending on when each period’s interest clock started

Total exposure before negotiation: $50,000–56,000 on $36,000 in underlying tax. The penalty and interest component exceeds 30–55% of the original tax.

A VDA would eliminate the $5,400 in penalties, potentially compress the lookback to 2 years (reducing the tax and interest proportionally), and close the liability with a defined agreement.

When penalties escalate further

Standard negligence penalties apply to sellers who failed to register or collect due to lack of knowledge or inadvertent non-compliance. Fraud penalties (reserved for intentional evasion) are significantly higher and can include criminal referral.

Collecting sales tax from customers and then not remitting it to the state is treated differently from simply failing to collect. Retaining collected tax is viewed as misappropriation of funds held in trust for the state, and several states treat it as a criminal matter in egregious cases.

The penalty structure under a VDA

A VDA agreement, in most states:

Waives all per-period penalties: the 10–25% per-period charges disappear
May limit the lookback to 3–4 years, reducing the underlying tax and therefore the interest base
Does not waive interest: you owe interest on the tax within the lookback window at the standard rate
Does not reduce the underlying tax: what was owed is owed; the VDA only removes the punitive charges

For most sellers with meaningful back-tax exposure, the penalty waiver alone justifies the VDA process.

Related: Can a VDA protect me from penalties and interest on past-due taxes? | I haven’t been collecting sales tax — what do I do now?

Frequently asked questions

What are the penalties for not collecting sales tax?

Penalties vary by state but typically run 10–25% of the unpaid tax per filing period. Some states add separate penalties for failure to register and failure to file. Interest accrues on the unpaid balance at roughly 0.5–1.5% per month (6–18% annually). On several years of back taxes, the combined penalty and interest can equal or exceed the underlying tax.

How is sales tax interest calculated?

Interest accrues on the unpaid tax balance from the original due date of each return. Most states use monthly or daily compounding at rates between 0.5% and 1.5% per month. Interest applies to the tax itself, not to penalties. A VDA typically doesn't waive interest, though it waives penalties.

What happens if you never file sales tax returns?

For unfiled periods, the statute of limitations typically doesn't run, states can reach back indefinitely in most cases. Penalties for completely unfiled periods are usually higher than for late-filed returns. The earlier you address it (through a VDA or retroactive filing), the smaller the total liability.

Can penalties be waived?

Yes, through a Voluntary Disclosure Agreement. VDAs routinely waive all penalties in exchange for voluntary compliance. Without a VDA, penalty abatement is harder to get, first-time penalty relief exists in some states but isn't guaranteed.

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