Glossary
What are comparable sales (comps)?
What are comparable sales, which closed sales qualify as comps, how to adjust them, and how comp coverage sets the confidence indicator.
Comparable sales, usually shortened to comps, are recent closed sales of nearby properties similar enough to the one you are underwriting that their prices stand in for its own. They are the evidence behind an after-repair value estimate, not an appraisal and not an asking price. On a Georgia tax deed, comps are the reason you can put a defensible number on a house you have probably never been inside.
What counts as a comparable sale
A comp is a price someone actually paid. Three other figures sit close to it on the page and get mistaken for one.
| Evidence | What it is | Weight in an after-repair value |
|---|---|---|
| Closed sale of a similar nearby home | A price a buyer paid | Primary |
| Active listing | What a seller is asking | Context only |
| Assessed value | The county's figure for taxation, set on an assessment cycle | None |
| A prior tax-sale price on the parcel | The result of a different kind of transaction | None for a retail resale |
The sale you want closed on the open market between unrelated parties on ordinary terms. A transfer between relatives, a move inside a family trust, or a bulk purchase by an investor tells you about that deal rather than about the neighborhood.
The rules that make a comp usable
Distance is the first filter and the weakest one. These matter more:
- Same submarket. The same subdivision where you can get it, then the same school zone and the same side of a dividing road. Price moves with those boundaries faster than it moves with mileage.
- Similar size, age, and layout. Square footage, year built, bedroom and bathroom count, one story against two, basement against slab.
- Repaired condition. An after-repair value is a finished-house number, so the comp has to be a finished house. Another distressed sale measures distress.
- Recent closings. Older sales describe a market that the eventual buyer's lender and appraiser will not be looking at.
- Ordinary terms. Arm's-length, no hidden seller concessions, no unusual financing propping up the price.
A comp that fails one of these is not worthless. It is weaker, and it should carry less weight than one that passes all five. How to pull comparable sales for a tax deed parcel walks through finding them for a specific address.
Adjusting for the differences that remain
No two houses match exactly, so the differences have to be priced:
- Add or subtract for the measurable items: finished square footage, a garage, an extra bathroom, a finished basement, a materially larger lot.
- Leave the unmeasurable alone rather than inventing a figure for it. If a comp differs in a way you cannot price, note it and lean on the comps that do not.
- Apply the same method to every parcel you underwrite. Adjustments that move to suit the bid you want are not analysis.
The more adjustment a comp needs, the less it proves. A handful of sales that need almost none support a tighter estimate than a long list that needs heavy ones.
From comps to a bid
Comps produce after-repair value, and after-repair value is the top of the subtraction every tax-deed bid comes out of: estimated rehab, which scales with square footage and year built, then legal and closing costs, carrying costs for the months you hold the parcel, and selling costs. What remains is the margin, and the margin sets the ceiling you bid to. How to set your max bid covers holding that ceiling once the bidding starts.
The other outcome runs on different arithmetic. If the former owner or another party holding an interest redeems within the 12-month right of redemption, you receive the amount you paid at the sale plus a redemption premium of 20% of that amount for the first year or fraction of a year, and 10% for each additional year or fraction. That premium is flat, not an interest rate, and it does not depend on your comps at all. Comps govern the other outcome: no redemption, barment and usually quiet title, and a property you now own and have to sell at something close to the value your comps described.
How comp coverage drives the confidence indicator
Comparable sales are not spread evenly. One parcel sits in a subdivision where near-identical houses close regularly; the next is an unusual cottage on an odd lot with few nearby sales to measure it against. An estimate can be produced in both cases, and the evidence behind the two is nowhere near equal.
That gap is what a confidence indicator exists to report. BidWise analyzes every parcel on a county's published tax-sale list, but only the parcels it can price from comparable sales receive a deal score from 0 to 100, and each score arrives with calculation notes and a confidence indicator reflecting how much comparable data stood behind the estimate. The score is a formula you can audit rather than a black box: after-repair value from comps, minus rehab, legal and closing costs, carrying costs, and selling costs, producing a margin that maps to the score. How to read your BidWise deal score takes the output apart field by field.
When the comps are not there
Some parcels cannot be priced from comparable sales, and saying so is more useful than producing a number anyway. Commercial and multi-family buildings, vacant land, and homes with too few nearby sales show the county's own figures instead of a score. BidWise covers five Georgia counties, DeKalb, Gwinnett, Cobb, Clayton, and Richmond, and Georgia has 159 counties, so beyond those five the comp work is yours from the start. The Georgia tax sales by county pages show each covered county's analyzed status, its next statutory sale date, and the official source it came from.
When a parcel has no usable comps, there are three honest options: price it on the land or the rent it could produce rather than on a resale, bid only an amount you would accept being repaid with the redemption premium, or pass. Guessing at an after-repair value you cannot support is the expensive option.
Frequently asked questions
What are comparable sales in real estate?
Comparable sales, or comps, are recent closed sales of nearby properties similar enough to a subject property that their prices can stand in for its own. Appraisers, agents, and investors all work from them to estimate value. A comp is a completed transaction, not a listing price and not a tax assessment, and the closer it matches the subject in location, size, age, condition, and timing, the more it proves.
How many comps do you need to price a tax deed parcel?
No fixed number makes an estimate sound. What matters is how closely the sales match the subject and how little adjustment they need to be comparable. A few near-identical closings in the same subdivision support a tighter estimate than a long list of distant or dissimilar ones. Where the usable sales are few, treat the result as a wide range rather than a single figure and bid accordingly.
Can you use the county's assessed value instead of comps?
No. An assessed value is the county's figure for taxation, produced on an assessment cycle rather than by a sale, so it can sit well above or below what a buyer would pay. It is useful as a sanity check and as a clue about the parcel's recorded characteristics, such as square footage and year built, but it is not evidence of market price. Only closed sales of similar nearby properties are.
Do previous tax-sale prices work as comps?
Not for a resale estimate. A Georgia tax sale conveys a redeemable tax deed subject to a 12-month right of redemption, with a different bidder pool and different terms than an ordinary sale, so the price reflects that transaction rather than what a repaired house is worth. Prior sale prices are still worth reading as history on the parcel, just not as after-repair evidence.
What does the BidWise confidence indicator mean?
It reports how much comparable sales data stood behind a parcel's estimate. Some neighborhoods produce many close, recent, similar closings; others produce few, and a value drawn from thin evidence deserves less weight even when the arithmetic behind it is identical. A deal score arrives with calculation notes and that indicator, so you can read both the number and the strength of the evidence underneath it.
Georgia tax sales convey a redeemable tax deed, not clear title. Every figure in BidWise is an estimate produced from public records and comparable sales — not an appraisal, and not investment, legal, or tax advice. Confirm every parcel against the county's official notice, and talk to a Georgia real-estate attorney before you bid.