If you sell a home in Duncanville in August or September, you will owe property taxes for a year that nobody has billed yet. Texas collects property taxes in arrears, so the 2026 bill does not exist on the day you close. Your title company still has to account for your share of it, so they estimate it and hand the buyer a credit out of your proceeds. On a typical Duncanville house that credit runs into four figures. Most sellers see it for the first time at the closing table.

The short answer

Texas property taxes are billed in arrears. When you sell mid-year, you credit the buyer for the days you owned the home from January 1 through your closing date, and the buyer pays the full bill when it arrives that fall. The credit is calculated from an estimate, usually the prior year's value and rate, because the current year's rate is not adopted until late September or later.

Steven's take on the tax proration line

Most agents sell houses. I build plans. On a Duncanville home closing September 15, 2026, the tax proration credit in the worked example below comes to $3,203.03. That is a real four-figure line item that belongs in your net sheet the day you decide to list, not on a settlement statement you are reading for the first time twenty minutes before you sign. Nothing about it is a surprise. It is arithmetic you can run in advance.

Why Texas bills property taxes in arrears

Texas property taxes cover a calendar year, January 1 through December 31, but the bill for that year does not go out until the fall of that same year. The sequence is set by statute.

• January 1 — the appraisal date. Values and exemption eligibility for the tax year are set as of this day under Texas Tax Code Section 11.42(a).
• By July 25 — the chief appraiser certifies the appraisal roll to each taxing unit under Tax Code Section 26.01(a). This is the Dallas Central Appraisal District handing Duncanville ISD, the City of Duncanville, Dallas County, Dallas College, and the Parkland Hospital District their taxable values.
• Late summer into fall — each taxing unit adopts its rate. Under Tax Code Section 26.05(a), a taxing unit must adopt its rate before the later of September 30 or the 60th day after it receives the certified appraisal roll.
• Around October 1 — the assessor mails tax bills under Tax Code Section 31.01(a).
• January 31 of the following year — taxes are due on receipt and become delinquent February 1 under Tax Code Section 31.02(a).

Line those dates up against a Duncanville seller closing on September 15, 2026. That seller owned the home for 258 days of the 2026 tax year. The 2026 bill will not be mailed for another two weeks or more, and will not be delinquent for another four and a half months. Someone has to pay for those 258 days, and it is not going to be the person who moves in on September 16.

What actually happens on the settlement statement

The mechanic is simple once you see it. The seller does not write a check to Dallas County at closing. The seller gives the buyer a credit — a debit against seller proceeds and a corresponding credit to the buyer — covering January 1 through the closing date. The buyer then pays the entire year's bill when the statement arrives that fall.

So the money moves once, at closing, and the tax office is paid once, in the fall, by the new owner. From your side as the seller it looks like a reduction in your net proceeds. From the buyer's side it looks like cash they are holding to cover a bill that includes months they did not own the house.

Two practical consequences follow. First, the later in the year you close, the larger your credit, because you owned the home for more of the tax year. Second, the credit is not optional and it is not negotiable in the way a repair allowance is. It is a mathematical allocation of a bill that already exists in concept even though it does not yet exist on paper.

The Duncanville tax rate stack

A Duncanville home inside Duncanville ISD is taxed by five entities. Here are the certified 2025 rates, published by the Dallas County Tax Office and the Dallas Central Appraisal District in its 2025 Ad Valorem Tax Rates schedule, revised November 5, 2025. These are the 2025 rates, and 2025 is the most recent year with certified rates as of this writing in August 2026.

Taxing unit	2025 rate per $100 of assessed value
Duncanville ISD	1.105700
City of Duncanville	0.600166
Dallas County	0.215500
Parkland Hospital District (Dallas County Hospital District)	0.212000
Dallas College (DCCCD)	0.106575
Combined	2.239941

That combined rate is about $2.24 per $100, or roughly 2.24 percent of assessed value before exemptions. The exemptions matter and they differ by entity. For tax year 2025, Duncanville ISD applied the $140,000 state residence homestead exemption. The City of Duncanville offered a 0 percent optional homestead exemption. Dallas County, Parkland, and Dallas College each offered a 20 percent optional homestead exemption. Those figures come from the same DCAD 2025 rate schedule.

A worked example: $285,000 Duncanville home, closing September 15, 2026

Take a Duncanville seller with a 2025 DCAD assessed value of $285,000 and a general residence homestead exemption. That value is close to the current market. Redfin reported a median sale price of $284,000 in Duncanville over the three months ending May 2026, down 6.9 percent year over year, with homes selling after an average of 47 days.

Step one is the full-year tax at 2025 rates and 2025 exemptions.

Taxing unit	Taxable value	2025 rate	Annual tax
Duncanville ISD	$145,000 ($285,000 less $140,000 homestead)	1.105700	$1,603.26
City of Duncanville	$285,000 (0% optional homestead)	0.600166	$1,710.47
Dallas County	$228,000 (20% homestead)	0.215500	$491.34
Parkland Hospital District	$228,000 (20% homestead)	0.212000	$483.36
Dallas College	$228,000 (20% homestead)	0.106575	$242.99
Total estimated annual tax			$4,531.42

Step two is the day count. 2026 has 365 days. January 1 through September 15 is 258 days: 31 in January, 28 in February, 31 in March, 30 in April, 31 in May, 30 in June, 31 in July, 31 in August, and 15 in September. That adds to 243 through the end of August, plus 15 more, for 258. The seller owned the home for 70.68 percent of the tax year.

Step three is the arithmetic.

• Daily tax: $4,531.42 divided by 365 = $12.4148 per day
• Seller's share: $12.4148 multiplied by 258 days = $3,203.03
• Buyer's share: $4,531.42 less $3,203.03 = $1,328.39

So the seller credits the buyer $3,203.03 at closing, and the buyer pays the full $4,531.42 bill when it arrives that fall. Run the same house closing on April 30 instead and the seller's share drops to 120 days, or about $1,489.78. Same house, same rate, same value — a $1,713 swing in net proceeds driven entirely by the calendar.

The same shape of math applies to DeSoto, Cedar Hill, and Lancaster sellers. The rates differ, so pull your own.

Why that number on your net sheet is an estimate

Here is the part most sellers never hear. On a September 15, 2026 closing, the 2026 tax bill does not exist. Duncanville ISD, the City of Duncanville, Dallas County, Parkland, and Dallas College may not have adopted their 2026 rates yet, and DCAD's 2026 values may still be under protest.

So the title company estimates. The common approach is to use the prior year's assessed value and the prior year's certified rate, which is exactly what the table above does — 2025 value, 2025 rate, applied to a 2026 closing. Some title companies use the current year's certified value with the prior year's rate. Others use whatever estimate DCAD or the county has published. Ask which method yours is using, because the three methods can produce meaningfully different numbers on the same house.

The estimate is wrong more often than it is exactly right. Values move. Rates move. In 2025 the certified Dallas College rate rose from 0.105595 to 0.106575, and the City of Duncanville rate fell from 0.614834 to 0.600166, according to the DCAD rate schedule. Small moves, but they compound across five entities on a value that also changed.

The exemption trap

This is where the estimate goes from slightly off to badly off.

The proration estimate is normally run off your account, which means your exemptions. If you are 65 or older, or a disabled veteran, or claiming a disabled person exemption, your annual tax on that Duncanville house is materially lower than the same house owned by someone who does not qualify.

Run the same $285,000 Duncanville home with an over-65 owner. For 2025, Duncanville ISD added a $65,000 over-65 exemption on top of the $140,000 homestead, the City of Duncanville added $40,000, and Dallas County, Parkland, and Dallas College each added $100,000, per the DCAD 2025 rate schedule. The annual tax drops from $4,531.42 to about $3,038.59 — a difference of roughly $1,493 for the year, before you account for the school tax ceiling under Tax Code Section 11.26, which can hold school taxes far lower still.

Now here is the problem. The general residence homestead exemption is set by January 1 status under Tax Code Section 11.42(a) and generally rides along for the tax year. The over-65 and disabled-person exemptions and the school tax ceiling attach to the qualifying individual, not to the house. When that owner sells, those come off, and the tax on the property is recalculated. The bill that lands in October can be well above the estimate the title company pulled off the seller's account in September.

Who eats the difference? Read your contract. Under Paragraph 13 of the TREC One to Four Family Residential Contract (Resale), the parties are obligated to adjust after the fact. A seller who closed in September and assumed the file was finished can get a call in November asking for more money. Confirm the specifics with your title company, your real estate attorney, and your tax professional — this is a description of how the mechanic works, not tax or legal advice.

What the TREC contract actually says

The relevant language is in Paragraph 13, PRORATIONS, of the TREC One to Four Family Residential Contract (Resale). TREC Form 20-19 became mandatory July 1, 2026, and carries the same proration language as the prior 20-18 version. It reads:

"Taxes for the current year, interest, rents, and regular periodic maintenance fees, assessments, and dues (including prepaid items) will be prorated through the Closing Date. The tax proration may be calculated taking into consideration any change in exemptions that will affect the current year's taxes. If taxes for the current year vary from the amount prorated at closing, the parties shall adjust the prorations when tax statements for the current year are available. If taxes are not paid at or prior to closing, Buyer shall pay taxes for the current year."

Three things in that paragraph matter to a Duncanville seller.

• "Prorated through the Closing Date." Your share runs January 1 through the day you close. That is the day count.
• "May be calculated taking into consideration any change in exemptions." The word is may, not will. Whether the estimate accounts for exemptions coming off is something to ask about, not something to assume.
• "The parties shall adjust the prorations when tax statements for the current year are available." The proration is not final at closing. If the actual bill differs from the estimate, both sides are obligated to true it up once the statement exists — which for a 2026 closing means roughly October 2026 through early 2027.

A true-up only happens if someone follows up, and after funding it is easy for both sides to let it go. That is a reason to get the estimate close at the table, not a reason to ignore the obligation.

Longer market times push closings later in the year

The proration split is driven by your closing date, and closing dates in this market are landing later than sellers plan for.

According to the MetroTex Association of REALTORS June 2026 housing report, released July 15, 2026, North Texas single-family homes spent an average of 54 days on market, up 4 percent from a year earlier. Active listings rose 4 percent year over year to 31,914 homes, with 4.4 months of inventory. The median sales price held flat at $405,000, and homes sold for about 95.5 percent of original list price. In Duncanville specifically, Redfin reported an average of 47 days on market for the three months ending May 2026, up from 40 days a year earlier.

Do the arithmetic on your own timeline. If you list July 1, take 54 days to go under contract, and run a 30-day close, you are signing around September 23. That is roughly a 73 percent tax proration split. List a month later and you are closing in late October at roughly 81 percent. Based on current conditions, later closings are the norm rather than the exception, and the tax credit grows with every week. No one can promise a specific timeline or outcome — but you can plan for the range.

What to do before you list

1. Pull your DCAD account. Go to dallascad.org and look up your property by address. Write down the 2026 assessed value, the 2025 assessed value, and every exemption showing on the account.
2. Confirm your exemptions are what you think they are. Homestead, over-65, disabled person, disabled veteran. If you turned 65 recently and never filed, that changes both your current bill and your proration estimate.
3. Ask the title company which year's rate they are estimating from. Prior year's rate on prior year's value, prior year's rate on current year's value, or a published estimate. Get the answer in writing before you are at the table.
4. Ask specifically whether the estimate assumes your exemptions carry. If you hold an over-65 exemption or a school tax ceiling, this is the single largest source of error in the number.
5. Put the credit in the net sheet on day one. Use the combined 2.239941 rate, your assessed value, your exemptions, and a realistic closing date. Recalculate when the closing date moves.
6. Do not close the file in your head at funding. Paragraph 13 keeps the proration open until the actual statement exists. Keep a note in your calendar for November.

What this means for your net sheet

• Texas bills property taxes in arrears — bills mail around October 1 and go delinquent February 1.
• A mid-year seller credits the buyer for January 1 through the closing date; the buyer pays the full bill later.
• The credit is an estimate, usually built on prior-year value and prior-year rate.
• The combined certified 2025 rate for a Duncanville home in Duncanville ISD is 2.239941 per $100.
• Over-65, disabled person, and disabled veteran exemptions attach to the owner, not the house, and can make the actual bill land above the estimate.
• TREC Paragraph 13 obligates both parties to adjust the proration once the real statement arrives.

Frequently asked questions

Do I pay my Duncanville property taxes at closing when I sell?

Not directly to the tax office. If the year's bill has not been issued yet, you credit the buyer for your portion of the year and the buyer pays the full bill when it arrives. If you close after the bill has been issued and it has not been paid, the title company typically pays it out of closing funds and prorates from there.

How is the tax proration calculated on a Texas home sale?

Estimated annual tax divided by 365, multiplied by the number of days from January 1 through the closing date. On a $285,000 Duncanville home with a homestead exemption and an estimated $4,531.42 annual tax, a September 15, 2026 closing produces a seller credit of $3,203.03.

Why is the proration on my net sheet only an estimate?

Because the current year's tax rates are not adopted until late September at the earliest under Tax Code Section 26.05(a), and bills do not mail until around October 1 under Section 31.01(a). Any closing before then has to use prior-year figures.

What happens if the actual tax bill is higher than the estimate?

Paragraph 13 of the TREC One to Four Family Residential Contract (Resale) says the parties shall adjust the prorations when tax statements for the current year are available. That can mean a request for additional funds after closing. Confirm how your title company handles the true-up.

Does my over-65 exemption transfer to the buyer?

No. Over-65 and disabled-person exemptions and the school district tax ceiling under Tax Code Section 11.26 are tied to the qualifying individual, not to the property. When you sell, they come off and the tax on the property is recalculated. Confirm the specifics with your tax professional.

Does closing later in the year cost me more?

Your proration credit grows as the year progresses because you owned the home for more of the tax year. A January 1 through April 30 closing on the example home produces about a $1,490 credit. The same home closing September 15 produces $3,203.03. Timing is not the only factor in a sale, but the tax line is one you can quantify in advance.

Build the number in before you list

Most agents sell houses. I build plans. The tax proration credit is arithmetic — a rate, a value, a set of exemptions, and a day count. There is no reason for it to be a surprise, and there is no reason it should not be sitting in your net sheet the week you decide to sell. That is the difference between a seller who knows their number and a seller who finds out what it is at the table.

Before you put a price on your Duncanville house, I want to walk through it with you in person and give you an honest read on where it stands.

Get your free Home Selling Score → https://stevenjthomas.com/get-your-home-selling-score

Steven J. Thomas, Broker, Refind Realty DFW, TREC Broker License #657467. 128 S. Cockrell Hill Rd, DeSoto, TX 75115. Call or text 972-846-9170.

This article is general information about how Texas property tax proration works and is not legal, tax, or accounting advice. Tax rates, assessed values, and exemption amounts change. Confirm your specific numbers with the Dallas Central Appraisal District, your title company, your own real estate attorney, and your tax professional. Market data reflects conditions at the time of writing and is not a prediction or a guarantee of any price, timeline, or outcome. Refind Realty DFW is an Equal Housing Opportunity broker. Texas Real Estate Commission Information About Brokerage Services and Consumer Protection Notice are available at trec.texas.gov.