Idaho Sales Tax Guide: Rate, Rules & Filing

Idaho levies a flat 6% state sales and use tax. Most of the state charges exactly 6%; a handful of resort cities add local-option taxes that push combined rates as high as 9%.

Most Idaho addresses are a flat 6%; resort towns like Sun Valley and McCall run higher. To find the combined rate for a specific address, use our US sales tax calculator.

Idaho economic nexus applies once your sales into the state exceed $100,000 in the current or prior calendar year. There is no transaction-count trigger. Physical presence creates nexus immediately.

Idaho requires marketplace facilitators that meet economic nexus to register, collect, and remit Idaho state sales and use tax on the retail sales they facilitate, under Idaho Code § 63-3620E; facilitators generally need a separate seller's permit for third-party marketplace sales in addition to any permit covering their own Idaho sales. A facilitator without physical presence in Idaho must begin collecting once its combined direct and facilitated sales exceed $100,000, while a facilitator with physical presence must collect starting with its first facilitated retail sale in the state. Facilitators remit only state sales and use tax — not local taxes or other taxes outside Idaho's sales tax chapter — and a marketplace seller is instructed to get written verification that a registered facilitator is reporting its sales, since the seller must otherwise include those sales on its own permit.[8]

Idaho assigns monthly, quarterly, or annual filing based on tax volume. Returns are due the 20th of the month following the reporting period. If the 20th falls on a weekend or holiday, the deadline moves to the next business day. For the portal, return, and step-by-step, see our guide to filing Idaho sales tax online.

Idaho taxes groceries but offers residents an annual grocery tax credit on their income tax to offset it. Prescription drugs are exempt. SaaS and electronically delivered software are not subject to Idaho sales tax.

Idaho buyers give the seller a completed Form ST-101 (Sales Tax Resale or Exemption Certificate) to buy for resale or under another exemption [5]. The seller keeps it on file and does not charge tax on future qualifying sales to that buyer [5].

For the official form, multistate certificate rules and expiry, see the Idaho resale certificate guide.

Late filing or payment carries a penalty of 5% of the tax due per month, up to a 25% maximum, with a $10 minimum, plus interest from the due date. Our Idaho filing guide lists late filing penalties, interest, and what to do if you missed a return.

After a Notice of Deficiency Determination, you have 63 days from the mailing date to file a written protest, or petition for redetermination, with the Tax Commission's Appeals Unit [6]. Certain jeopardy and IFTA/IRP assessments carry a shorter 30-day window [6].

• [1] Idaho State Tax Commission — Sales and Use Tax Guide (6% rate, groceries, digital)

• [2] Idaho STC — Online Sellers (economic nexus)

• [3] Idaho STC — Retailers Collecting Tax (SaaS not taxable)

• [4] Idaho STC — Grocery Credit

• [5] Idaho STC — Form ST-101 (Resale or Exemption Certificate)

• [6] Idaho STC — Right to Appeal (63-day protest)

• [7] Idaho STC — Business Registration (TAP)

• [8] Idaho State Tax Commission — Idaho Code § 63-3620E (Marketplace Facilitators)

Verified July 2026 against Idaho State Tax Commission published guidance.

• Understanding Digital Products Sales Tax in Idaho: What Businesses Need to Know