Building a comps list for dozens of tax appeals without the manual grind

If you consult on property tax appeals, you already know the part of the job nobody puts in the brochure: before you can argue that your client's assessment is too high, you have to build a defensible list of comparable properties. And when appeal season hits, you're not doing this for one client. You're doing it for dozens, all at once, all with deadlines that don't move.

Every comp needs to be a real, locatable address. Every comp needs to sit at a sensible distance from the subject property, in the right neighbourhood, on the right side of whatever line matters for that jurisdiction. And every one of those addresses has to end up plotted somewhere — on a map for your own sanity check, in an exhibit for the appeal board, or layered against parcel boundaries so you can prove the comp is actually comparable.

The addresses themselves usually aren't the problem. You can pull them from county records, MLS exports, or your own running database. The problem is what happens next: turning a flat list of street addresses into locations you can actually map, measure, and present. Done by hand, that's an afternoon per appeal. Multiply that by thirty or forty appeals in a season, and you've lost weeks to a task that has nothing to do with your actual expertise, which is arguing valuation.

What this actually costs you right now

Say you're building comps for 35 appeals this cycle, with 15 comparable properties per file. That's 525 addresses. If you're locating each one manually — searching, copying coordinates, pasting into a mapping tool, checking it landed in the right spot — even a fast pace of two minutes per address is over 17 hours of pure, repetitive lookup work. That's before you've written a single page of the actual appeal argument.

And manual lookup isn't just slow, it's inconsistent. Different staff members (or you, on hour six of a lookup marathon) will handle a messy address differently — a misspelled street name, a rural route number, a condo unit that got typed into the wrong field. Some get skipped. Some get placed slightly wrong, which doesn't matter until an assessor's rebuttal points out that your "comparable" property is actually half a mile further from the subject than your exhibit claims. In this line of work, a sloppy comp map isn't just embarrassing — it can undercut the whole appeal.

Then there's the client-facing cost. Appeal boards and assessors expect professional documentation. A comps exhibit that's clearly been eyeballed onto a map, with pins in slightly wrong places, looks amateurish next to one where every location is precise and consistent. That difference can be the thing that makes an appeal look credible or not.

The fix: treat address-to-location as a solved problem

The part of this job that eats your time — turning a list of addresses into usable map locations — doesn't need to be done by hand, and it doesn't need a GIS background or any software beyond the spreadsheet you already use. You upload the list of comp addresses as a spreadsheet, and you get back the same spreadsheet with a location added to every row: latitude and longitude for each property, ready to drop into a map, a mail-merge exhibit, or a distance calculation.

You do this instead of manually searching each address once — and instead of doing it again for the next appeal, and the next, and the one after that during peak season. That's why it makes more sense as an ongoing subscription than a one-off tool: it's the same repetitive task every single filing cycle, for as long as you're in this business.

Why a subscription beats doing it ad hoc

If you were only pulling comps for two or three appeals a year, a subscription wouldn't make sense — you'd just look them up manually. But if you're a working consultant handling appeals in batches, all year or in seasonal waves, the volume adds up fast enough that a subscription is meaningfully cheaper and faster than paying per file or per lookup every time.

The Starter plan at $49 a month covers up to 50,000 US addresses a month. For most independent consultants and small firms, that's not a number you'll come close to hitting even in your busiest filing season — 50,000 addresses would cover roughly 3,300 appeals at 15 comps each. It's cancel-anytime, so if you only do this seasonally, you can run it during appeal season and pause it the rest of the year. Subscribing this way also runs up to 30% cheaper than paying per address with no plan at all, which matters if you're doing this every cycle rather than once.

How it works

Step 1: Pull your comp addresses into one spreadsheet

Export or compile the addresses for all your comps across every appeal you're working this cycle — one row per property, with the address in its own column or columns. It doesn't matter if these come from different sources; as long as they end up in one file, you can process the whole batch together.

Step 2: Upload the file

Log in and upload the spreadsheet. There's nothing to configure and nothing to install — it works the same way as attaching a file to an email.

Step 3: Let it run

The service reads every address in the file and looks up its precise location. For a batch of a few hundred properties, this finishes in minutes, not hours.

Step 4: Download your finished spreadsheet

You get back the exact same file, with new columns added for latitude, longitude, and a normalised version of the address. Nothing you already had is removed or rearranged — it's your original file, completed.

Step 5: Drop the results straight into your exhibit or map

From there, the locations are ready to plug into whatever mapping or presentation tool you already use for the appeal board — no manual re-entry, no copy-pasting coordinates one at a time.

What this changes at appeal time

The obvious win is time — hours of manual lookup collapse into minutes, freeing you up to spend the season on valuation arguments instead of data entry. But the more important win is consistency. Every comp in every exhibit gets located the same way, to the same standard, whether it's the first appeal of the season or the fortieth filed at 11pm before a deadline. That consistency is exactly what holds up under scrutiny when an assessor's office pushes back on your comps.

It also means you can take on more volume without adding headcount. A two-person consultancy that used to cap itself at a certain number of appeals per season because the manual comp work was the bottleneck can take on more clients, because the bottleneck is gone.

Objections, answered honestly

"My addresses are messy — county records, MLS exports, handwritten notes typed up by an assistant." That's normal, and it's exactly the kind of file this is built to handle. Most real-world address lists have inconsistent formatting, abbreviations, and the odd typo. The service is built to work with realistic, imperfect data, not a pristine list. If a handful of addresses genuinely can't be resolved — because they're incomplete or the property doesn't have a standard mailing address — those rows are flagged clearly in your results, so you can fix them by hand instead of guessing which ones failed.

"I don't have anyone technical on my team." You don't need one. If you can attach a file to an email, you can run this yourself, start to finish.

FAQ

Is this hard to set up if I'm not techy at all? No. If you can attach a file to an email, you can use this. There's no software to install and no settings to configure — you upload a spreadsheet and download a finished one.

What happens if some of my comp addresses are incomplete or oddly formatted? The service does its best to resolve messy, real-world addresses, including typos, abbreviations, and inconsistent formatting. Any address it genuinely can't locate is clearly marked in your results, so you know exactly which ones to check by hand rather than guessing.

How much does the plan I'd actually need cost? The Starter plan is $49 a month and covers up to 50,000 US addresses. For most consultants, even a heavy appeal season won't come close to that ceiling.

Can I cancel if I only need this during appeal season? Yes. The subscription is month-to-month with no lock-in, so you can run it during your busy filing months and pause it the rest of the year.

Is my client and property data safe? Yes. You're uploading a spreadsheet to process a batch job and getting your results back — it isn't shared, sold, or used for anything beyond completing your request.

Do I need any GIS or mapping experience to use this? No. The output is just your original spreadsheet with location columns added. What you do with it afterwards — dropping it into a map, an exhibit, or a distance calculation — uses whatever tools you already work with.

What if I only handle a handful of appeals a year, not dozens? If your volume is genuinely small, a subscription may not be worth it — occasional pay-as-you-go use might suit you better. This approach earns its keep once you're processing comps in batches every filing cycle.

Related articles

• The real cost of running your own geocoder
• Handling addresses that won't geocode
• A one-week geocoding pilot playbook
• Pitching geocoding spend to your CFO
• Run geocoding for every client under one team plan

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*I.A. / CSV2GEO Creator*