Yes! You can use AI to fill out Form ST-105, General Sales Tax Exemption Certificate

Users often provide the wrong type of ID number or enter it incorrectly. For example, an out-of-state purchaser might leave the ID section blank, or a farmer might provide a State ID instead of the requested SSN or FID. An invalid or missing ID number will cause the seller to reject the certificate and charge sales tax, as it is a mandatory field for validating the exemption. To avoid this, carefully read the instructions for Section 1 to determine the correct ID type for your business category; AI-powered tools like Instafill.ai can help by validating number formats and guiding users to the correct field based on their entity type.

In Section 2, purchasers frequently forget to check either the 'blanket purchase' or 'single purchase' box, making it unclear if the certificate applies to one transaction or all future qualifying purchases. An incomplete form may be rejected by the vendor, forcing them to charge sales tax until a corrected certificate is provided. Always check one of the two boxes to clearly define the scope of the exemption request.

Purchasers often write a generic description like 'parts' or 'supplies' in Section 2, which is insufficient for a seller to verify that the items qualify for the claimed exemption. This creates audit risks for the seller, who may then reject the form and charge tax to protect themselves. Be specific by listing the types of items, such as 'steel components for manufacturing' or 'cardboard packaging for resale,' to create a clear record.

In Section 3, a user might select an exemption category that doesn't accurately reflect their business or the item's use, such as claiming a 'resale' exemption for equipment that will be used in production. This constitutes misuse of the certificate and can lead to penalties, interest, and back taxes for the purchaser if discovered during an audit. Carefully review each exemption category and select the one that precisely matches your legal eligibility.

Certain exemptions in Section 3 require additional information that is often missed, such as providing a USDOT number for a public transportation exemption or an agency name for a federal government exemption. Failure to provide this linked information invalidates the specific exemption claim, forcing the seller to collect sales tax. Double-check if your selected exemption requires an additional ID or name and ensure it is filled in the correct space.

It is extremely common for purchasers to leave the signature, date, printed name, or title fields in Section 4 blank. An unsigned or undated certificate is legally invalid and cannot be accepted by the seller, leading to immediate rejection and the collection of sales tax. Always complete all fields in the certification section to attest to the accuracy of the information under penalty of perjury.

Indiana-based purchasers often enter their Taxpayer Identification Number (TID) and Location Code (LOC) incorrectly, as the form requires a specific 10-digit TID and 3-digit LOC. Users may transpose digits, omit numbers, or enter them in the wrong fields, which prevents the seller from verifying the purchaser's registration. To prevent this, copy the numbers exactly as they appear on your certificate; using a tool like Instafill.ai can help auto-populate and format these numbers correctly.

The form explicitly states it cannot be used for the purchase of Utilities, Vehicles, Watercraft, or Aircraft, but purchasers sometimes overlook this restriction. Attempting to use the certificate for these non-qualifying items is a direct violation of the form's terms and will be rejected by the seller. Misuse can also lead to penalties, so always confirm that the items you are purchasing are eligible for exemption with this specific form.

Purchasers sometimes enter their 'Doing Business As' (DBA) name instead of the full legal entity name registered with the state. This can create a mismatch when the seller attempts to verify the business's tax-exempt status against official records, leading to the rejection of the form. Always use the official legal name of the business as it appears on your state registration documents to ensure a smooth validation process.

When filling out a paper copy, purchasers often have illegible handwriting, especially in the name, address, and ID number sections. If the seller cannot accurately read the information, they cannot verify its validity, rendering the certificate useless. To avoid this, print clearly in block letters or use a fillable version of the form. Since this form is often a non-fillable PDF, a service like Instafill.ai can convert it into an interactive, fillable format to ensure all entries are typed and perfectly legible.