How to Fill Out and Submit the Indiana BT-1 Business Tax Application

The Indiana BT-1 business tax application is the single form you file with the Indiana Department of Revenue to register a new business for sales tax, employer withholding, and several other state tax types. You submit it online through the INBiz portal at inbiz.in.gov, and if you’re registering for sales tax you pay $25 for each business location to receive a Registered Retail Merchant Certificate.¹ Most online filings take effect within a few days.

What the BT-1 Actually Registers

The BT-1 is a combined application, so you check the boxes for the tax types that fit your business and skip the ones that don’t. The categories available on the form are:

Sales tax, for any business selling tangible personal property at retail. Indiana’s rate is seven percent, and you cannot legally make retail sales until your Registered Retail Merchant Certificate is issued.¹
Withholding tax, for employers who pay wages and need to withhold state and county income tax.
Food and beverage tax, for sellers of prepared food and drink in counties that impose it.
County innkeeper’s tax, for hotels, motels, and similar lodging.
Motor vehicle rental excise tax, for vehicle rental businesses.
Gasoline use tax, for certain commercial gasoline uses.

Rates for the food and beverage tax and the innkeeper’s tax vary by county, but registration and remittance run through the Department of Revenue.²

What to Have Ready Before You Start

Gather everything before you open the application. Once you’re in the form, missing information sends you back out to look for it, and you’ll want your Document Locator Number (DLN) written down so you can return to a saved draft.³

Your Federal Employer Identification Number from the IRS. Sole proprietors without an EIN can use their Social Security Number.
Your legal business name exactly as registered with the Indiana Secretary of State. Corporations, LLCs, and limited partnerships also need their Secretary of State control number.
Your type of organization: sole proprietorship, general partnership, LLC, S corporation, C corporation, or other.
Your six-digit NAICS code describing your primary business activity. The Department of Revenue uses this to identify which tax obligations apply.
Names and Social Security Numbers for all owners, partners, or corporate officers. These are the responsible individuals the state ties to the business’s tax liabilities.
The physical address and phone number for each business location. Multiple locations are registered inside the same application.
The primary mailing address for state correspondence.
The specific tax types you’re registering for from the list above.

The system generates your DLN as soon as you begin. Save it immediately; it’s how you get back into a filing in progress and how you reference it later.³

How to Submit the Application

Online Through INBiz

INBiz at inbiz.in.gov is Indiana’s business registration system and the primary route for filing the BT-1. Don’t confuse it with INTIME, the Indiana Taxpayer Information Management Engine, which is the separate portal you’ll use later to file returns and make payments once your accounts exist.³ The online form walks you section by section, and you pay the $25-per-location retail merchant fee electronically if sales tax is one of your selections.¹

Paper Filing by Mail

A paper BT-1 is available on the Department of Revenue’s website for businesses that can’t file online. Processing takes longer because entries are keyed by hand. If you’re registering for sales tax, include a check or money order for $25 per location. Verify the current mailing address on the paper form itself before sending it in.

What You Receive After Filing

Your Taxpayer Identification Number

Once your BT-1 is processed, the Department of Revenue issues an Indiana Taxpayer Identification Number, or TID. The TID is ten digits, and each business location gets its own three-digit location (LOC) suffix. The full TID-LOC combination goes on your returns, exemption certificates, and any correspondence with the state.⁴ Online filings generally clear faster than paper. The department does not publish a guaranteed turnaround. You’ll use your TID together with a Letter ID from DOR correspondence to set up your INTIME account.⁵

Your Registered Retail Merchant Certificate

If you registered for sales tax, the state issues a Registered Retail Merchant Certificate for each location on your application, each with its own serial number tied to that address.¹ You are required to display the certificate at each place of business. If you open another location later, you file a supplemental application and pay another $25 for that site.⁶

How Often You’ll File Returns

The Department of Revenue sets your filing frequency based on your average monthly tax liability, and this applies to both sales tax and withholding. If your liability shifts during the year, the department can move you to a different schedule and will notify you before the next tax year. Any business whose average monthly tax exceeds $5,000 must pay by electronic funds transfer.⁶

File every period, even when you owe nothing, until the account is formally closed. Skipping a zero return doesn’t end the obligation; the department will issue a bill based on the information it has.⁷

If You’re Buying an Existing Business

The BT-1 asks whether you’re acquiring an existing business, and this is not a routine question. Under Indiana law, a buyer who takes possession of business assets without first notifying the Department of Revenue can be held personally liable for the seller’s unpaid taxes, up to the full purchase price.⁸

Either the buyer or the seller must notify the department at least 45 days before the buyer takes possession or pays the purchase price. The department then has 20 days to respond. If the seller is clean, you receive a tax clearance letter confirming no successor liability. If the seller owes tax, you receive a summary of the amount, and you are expected to withhold that amount from the purchase price and remit it to the state.⁸ A contract clause assigning tax debts to the seller does not override the statute.

Remote Sellers Without an Indiana Location

You don’t need to be located in Indiana to be required to register. If your gross revenue from sales into Indiana exceeds $100,000 in the current or previous calendar year, you have economic nexus and must file the BT-1 to collect and remit sales tax. Indiana repealed the transaction-count threshold effective January 1, 2024, so only the dollar figure applies.⁹ Sales you make through a registered marketplace facilitator, which collects on your behalf, do not count toward your own threshold.¹⁰

After Registration: Updates and Closures

Once registered, you’re responsible for keeping the information current. Address changes, new responsible officers, and location changes go through INTIME or directly to the Department of Revenue using its posted forms.⁷ The department can deny or refuse to renew a retail merchant certificate if the business is operated, managed, or affiliated with a person who has failed to file returns or pay taxes owed, and it treats a substantially similar new business by a person with outstanding tax debts as a red flag.¹

When you stop operating in Indiana, close your accounts formally. Leaving them open keeps returns coming due, and missing returns produce estimated tax bills. In INTIME, select Close Business Tax Accounts under Tax Account Registration; you can close the whole business, one location, or specific tax types at a location. The cease date cannot be later than the end of the following month. Corporations dissolving must complete their final corporate return before submitting a dissolution request on Form IT-966 through INTIME.⁷

1
Indiana General Assembly. Indiana Code 6-2.5-8-1 – Registered Retail Merchants Certificate Application Filing Fee
2
Indiana Department of Revenue. Business Tax Forms
3
Indiana Department of Revenue. Business Tax Application Checklist
4
Indiana Department of Revenue. General Sales Tax Exemption Certificate Form ST-105
5
Indiana Department of Revenue. Withholding Income
6
Indiana Department of Revenue. Business FAQ
7
Indiana Department of Revenue. INTIME Guide for Business Tax Customers
8
Indiana General Assembly. Indiana Code Title 6 Taxation 6-8.1-10-9.5
9
Indiana Department of Revenue. Remote Seller
10
Indiana Department of Revenue. Sales Tax Information Bulletin 89