Connecticut Business Personal Property Tax: Declaration Deadline, Penalty and Exemptions

Most new Connecticut owners register the LLC or corporation, get a sales tax permit, and assume the tax paperwork is done. There is one more filing, and it goes to your town, not to Hartford. It is the annual declaration of business personal property. If your business owns desks, computers, machinery, tools, shelving or other movable equipment, your town assessor may tax it every year, and the declaration is due November 1. This is the town-level tax most new owners miss.

This guide covers what the declaration includes, when it is due, what it costs you if you miss it, and which exemptions can lower the bill. The rules come from the Connecticut General Statutes (CGS) and your town's assessor, so confirm the details for your town before you rely on them.

What counts as business personal property

Business personal property is tangible property that your business owns and uses. That means things you can touch and move. Common examples include:

• Office furniture, desks, chairs and filing cabinets
• Computers, printers, phones and other electronics used in the business
• Machinery, tools and production equipment
• Shelving, display cases, signs and store fixtures

Two categories are handled differently. Real estate, meaning land and buildings, is assessed separately from personal property. Motor vehicles registered with the Department of Motor Vehicles (DMV) are also left off the declaration. If you are unsure whether an item belongs on the list, ask the assessor before you leave it off, because omitted property has its own penalty (covered below).

Who you file with, and what is not the filing

You file with the town assessor in the town where the property sits on October 1, the assessment date. The filing goes to the town. It does not go to the Connecticut Secretary of the State or the Department of Revenue Services (DRS). Connecticut has no county government, so no county office is involved at any step.

The state filings you may already have are separate from this one. Your LLC's Annual Report is filed with the Secretary of the State through Business.CT.gov. Your Sales and Use Tax Permit comes from DRS, and the state's DRS portal covers state tax questions. Neither one replaces the personal property declaration. A trade name certificate, which you need if you do business under a name other than your legal name, is filed with the town clerk. Owners often mix up that town clerk filing with the assessor filing, so keep them straight.

The November 1 deadline

The declaration is due to the assessor by November 1 each year. It covers property you owned on October 1. Equipment you bought in November goes on next year's list. Equipment you sold before October 1 does not belong on this year's list.

Two timing rules matter:

• If November 1 falls on a weekend, the deadline moves to the next business day. In 2026, November 1 is a Sunday, so the deadline is Monday, November 2, 2026.
• A postmark counts. A declaration postmarked on or before the deadline is on time. Keep a copy of what you filed and your mailing receipt.

Start the list in September, not on October 31. The declaration reflects what you owned on October 1, so the records you need are the ones from that date.

How the value and the tax are figured

Town assessments are set at 70% of value (CGS 12-62a). If your equipment is worth $20,000 on the assessment date, the assessed value is $14,000.

The tax is the assessed value multiplied by your town's mill rate. A mill is one dollar of tax for every $1,000 of assessed value. Each town sets its mill rate every year, so check with your town assessor or tax collector for the current figure. As a hypothetical only, if the mill rate were 30, the tax on that $14,000 assessment would be $420. Your town's actual rate may be higher or lower.

What happens if you miss the deadline

If you do not file a declaration, the assessor prepares one for you and adds a 25% penalty (CGS 12-42). You do not get to supply the figures in that case. The assessor works from the information available to them.

The penalty also applies to omitted property. If you file on time but leave equipment off the list, that equipment carries a 25% penalty when it is found. A timely filing is not enough on its own. The list needs to be complete.

Requesting an extension

If you need more time, you can request an extension of up to 45 days, but the request must be made in writing by November 1 and must show good cause (CGS 12-42). A phone call does not meet the written requirement. What counts as good cause is up to the assessor, so check with them before you assume a reason will be accepted.

Exemptions that can lower the bill

Qualifying machinery and equipment

Machinery and equipment used in manufacturing, biotechnology or recycling can be exempt under CGS 12-81(76). The exemption requires a claim filed with the assessor by November 1. It is not automatic. If you miss the claim deadline, plan on the property being taxed for that year. Ask the assessor how they define qualifying use for your operation, because the classification can turn on how the equipment is actually used.

Low-value property

Property with an original value of $250 or less is exempt, but only after its first ten full assessment years (CGS 12-81(79)). It is not exempt in the years before that. A low-cost item bought this year will still appear on your declaration.

What is not an exemption

Connecticut has no $10,000 de minimis exemption. Many owners assume that a small total value falls below a threshold and can be skipped. It cannot. Every item of taxable property must be listed unless a specific exemption applies.

Closing, moving and selling equipment

If you close the business, move out of town or sell equipment, tell the assessor. Assessor guidance in Connecticut towns, such as Meriden's, asks owners to report a closure or move, and property you no longer own should not remain on the list. The October 1 rule still controls which town gets the declaration, so a move made after October 1 can leave you filing in the old town for that year.

Key figures at a glance

Item	Figure or rule	Source
Assessment date	October 1	CGS 12-41
Filing deadline	November 1 each year, next business day if a weekend	CGS 12-41
Assessment ratio	70% of value	CGS 12-62a
No declaration filed	Assessor prepares one and adds 25%	CGS 12-42
Omitted property	25% penalty	Penalty rule as stated in this guide
Extension	Written request by November 1, good cause, up to 45 days	CGS 12-42
Manufacturing, biotechnology or recycling equipment	Exempt if a claim is filed by November 1	CGS 12-81(76)
Original value of $250 or less	Exempt only after the first ten full assessment years	CGS 12-81(79)
Mill rate	Set by each town every year	Check with your town assessor

Common mistakes

• Listing only the large items and skipping small equipment. There is no $10,000 de minimis exemption.
• Assuming the Annual Report or sales tax permit covers the town declaration. It does not.
• Building the list in late October from memory. The list reflects October 1 ownership, so start from records dated before then.
• Missing the November 1 claim for qualifying machinery and equipment. The claim is separate from the declaration.
• Leaving closed or sold equipment on the list, or failing to report a move.

What to confirm with your assessor

This guide cannot give you your town's specific answers. Check with your town assessor on these points:

• The current mill rate, and when your tax bill is due (check with the town tax collector as well)
• The declaration form your town uses, and whether it accepts online filing
• Whether equipment kept at home for the business is treated as business personal property
• Whether leased equipment belongs on your declaration or on the lessor's
• What your town accepts as qualifying use for the machinery and equipment claim

Next steps

1. Build an inventory of business property as of October 1, with purchase dates and costs.
2. Get the declaration form from your town assessor's office and confirm the filing method.
3. Decide whether any equipment qualifies for the machinery and equipment claim, and file that claim by November 1.
4. File the declaration by November 1, or the next business day if the deadline falls on a weekend. Keep a copy and proof of mailing.
5. If you cannot finish in time, request an extension in writing by November 1.

This guide is informational content, not legal or tax advice. Connecticut rules and town practices change, and this page may not reflect the current version of a statute or your town's procedures. For complex situations, such as leased equipment, property in several towns, or a large machinery claim, talk with a qualified CPA or attorney who works with Connecticut businesses.