Why your Detroit tax bill jumps after buying
Detroit property tax uncapping is the moment your taxable value resets to match assessed value on the day you buy. The seller may have paid taxes on a taxable value frozen for years by Proposal A. You pay on the full current value. That gap can be thousands of dollars a year.
If michigan taxable value uncaps on transfer, your first summer tax bill after closing can be double or triple what the listing showed. If detroit taxes jumped after buying, this is usually why.
How Proposal A caps the seller's taxable value
Proposal A, passed in 1994, limits how much a home's taxable value can grow each year while the same owner holds it. Taxable value can rise by no more than 5% or the rate of inflation, whichever is lower. Assessed value, by contrast, is supposed to track true market value.
Over 10 or 20 years, the spread between assessed value and taxable value can become enormous. The seller pays taxes on the capped, lower taxable value. The cap belongs to the owner, not the house. When the property transfers, the cap dies.
The day of transfer: taxable value resets
On December 31 of the year after transfer, the taxable value resets to the assessed value as of the transfer date. In practice, that means your first full tax year after buying starts at the uncapped number.
Here is the math on a realistic Detroit example:
| Line item | Amount | |---|---:|---| | Seller's assessed value (what the city says it is worth) | $85,000 | | Seller's taxable value (capped by Proposal A) | $22,400 | | Detroit 2026 total millage rate, city + library + schools + county | 69.5 mills | | Seller's 2025 tax bill (22,400 ÷ 1,000 × 69.5) | $1,557 | | Buyer's first uncapped tax bill (85,000 ÷ 1,000 × 69.5) | $5,908 | | Annual tax increase | $4,351 |
The buyer's bill in this example is 279% higher than the seller's. That is not a penalty. It is the removal of the cap.
In 2026, Detroit's total millage rate varies by address because of school district and special assessment differences. But the math is the same everywhere in Michigan: after transfer, taxable value equals assessed value.
File the Property Transfer Affidavit within 45 days
Under MCL 211.27a, the buyer must file a Property Transfer Affidavit with the local assessor within 45 days of closing. The form tells the assessor who now owns the property and what they paid. The assessor uses it to set the new taxable value.
If you miss the 45-day deadline, the penalty is $5 per day, up to a maximum of $200. The form is available from the Detroit Office of the Assessor or online at Michigan.gov.
Claim the Principal Residence Exemption if you live there
If you own and occupy the home as your principal residence, you can claim the Principal Residence Exemption (PRE). The PRE exempts 18 mills of school operating tax. On a $85,000 taxable value, that saves:
$85,000 ÷ 1,000 × 18 mills = $1,530 per year
You must file the Principal Residence Exemption Affidavit (Form 2368) with the assessor by May 1 for the exemption to apply to that year's summer tax bill. If you buy after May 1, the exemption will not reduce the current summer bill, but it will apply to the winter bill and future years.
If you do not live in the home and rent it out, you cannot claim the PRE. The rental will be taxed at the full millage rate, including the 18 mills of school operating tax.
What the buyer should do before closing
Before you sign, ask the assessor for the property's current taxable value and assessed value. The Office of the Assessor at the Coleman A. Young Municipal Center can provide both. Then do the uncapping math yourself: assessed value × millage rate ÷ 1,000 = your first year's approximate tax bill.
Across Detroit, roughly 75,566 parcels carry unpaid blight-ticket debt, and older homes often have open code enforcement items that the buyer inherits. Check the address against city records before you commit.
You can also order a one-time property report for the specific address you are buying or selling. It pulls the city's records on tickets, liens, water balances, and compliance history into one document.
How does the city know I bought the property?
Your Property Transfer Affidavit tells the city. Most title companies file it at closing, but the legal duty is yours. The assessor also receives deed recordings from the Wayne County Register of Deeds. If you do not file within 45 days, the assessor will eventually spot the transfer and backdate the uncapping, plus the per-day penalty up to $200.
Can I keep the seller's lower taxable value?
No. Proposal A's cap is personal to the owner. It never transfers. On the December 31 after your purchase, taxable value resets to assessed value. There is no hardship exception for uncapping, and you cannot appeal the reset just because the new bill is higher.
How can I avoid a tax surprise next year?
Before you close, call the Detroit Office of the Assessor or look up the property online. Multiply the assessed value by the latest millage rate for that address. That is your first-year tax bill, not the seller's. Then check for any open liens or tickets that will also attach to the property. A Detroit real estate attorney can review the full picture if the purchase price is high enough to justify it.
Sources
- Michigan Department of Treasury, Property Transfer Affidavit and PRE guidance
- Michigan Legislature, MCL 211.27a (uncapping of taxable value)
- Detroit Office of the Assessor
- Detroit blight ticket statistics
To see everything the city has on file for your address, including unpaid tickets, water liens, and the current taxable value, look it up free at detroitcompliance.com/lookup.