The 7 Biggest Mistakes Coin Collectors Make When Hunting Overdates (And How to Avoid Them)

I’ve watched collectors make these same mistakes for years. The difference between finding a $5,000 overdate and wasting hundreds on a fake often comes down to these seven critical errors.

Overdates – coins where a new date was punched over an old one – are like time capsules. That 1942/1 Mercury dime? It’s proof of mints scrambling during WWII. The 1817/3 Capped Bust half? A glimpse into early 19th-century mint operations. These stories make overdates the most exciting finds in numismatics.

But here’s what most people get wrong. After authenticating thousands of these coins and working with top graders, I’ve seen how easily you can miss the real thing, mistake damage for an overdate, or overpay for something questionable. Let’s fix that.

1. Confusing Die Doubling with Real Overdates

This mistake has cost collectors dearly. The difference is subtle but everything.

Die Doubling Red Flags

<
• Lines that match the original digit’s angle – like shadows

<

• Even gaps between the “double” and original lines

<

• No actual metal displacement – it’s all on the surface
• Appears across multiple parts of the coin, not just the date

What to Look For Instead

True overdates show physical metal movement. Watch for:

<
• Warped metal where the new digit was hammered into the old

<

• Bumps or ridges at the edges from displaced metal

<

• Deeper impression where the overpunch sits

Take the 1829/7 Half Dollar. The “7” should be punched right into the “9”, with metal visibly pushed aside at the crossing points. A 10x loupe is essential – you need to see that third dimension.

What to Do If You Slip Up: Buy a coin that turns out to be die doubling? Contact the grading service fast. Most will re-examine it if you’re disputing authentication. Take clear photos from multiple angles to support your case.

2. Bad Photography That Masks the Truth

I’ve lost count of “overdates” that vanish under proper magnification. Bad photos are the enemy of the overdate hunter.

Photos That Should Raise Suspicions

<
• Shadows shaped like damage from bad lighting

<

• Glare covering the date area

<

• Pixelated images that hide fine details

<

• Angled shots that make normal doubling look like overpunching

How to Get It Right

Here’s what works for me:

• Macro lens only – no phone cameras
• Soft, diffused lighting – light tent or LED panels at 45°
• Photos straight down, plus 10° and 20° angles
• Scale included (mm for small coins, ruler for big)
• RAW format for editing flexibility

// How I set up my tent
// 1. Neutral background, centered coin
// 2. Two LED panels at 45° angles
// 3. White reflector card underneath
// 4. 12-18" distance for soft light
// 5. Manual focus on date
// 6. f/16 for full detail

What to Do If You’re Unsure: Not convinced by a seller’s photos? Ask for more. Good dealers will send additional angles. For your collection, a $200 setup pays for itself in mistakes avoided.

3. Missing the Die Stage Story

Overdates evolve as dies wear. Collectors often only chase early-state coins, missing value or making bad calls.

Die Stages That Matter

• Early: Sharp overpunch, clear digit separation
• Middle: Some wear, but most detail remains
• Late: Heavy wear, overpunch may seem to blend
• Terminal: Die cracks might hide the overdate

What Most Get Wrong

Don’t assume heavy wear means worthless. Some late-state overdates are rarer. The 1817/3 Capped Bust half has a die crack version that trades for multiples of early-state prices.

Wear rarely erases the overdate completely. Even in VF condition, look for the “ghost” of the old digit in the metal’s flow. The pushed metal tells the story when digits fade.

What to Do Instead: Study die progression charts. References like Cherrypickers’ Guide show these changes. For worn coins, focus on metal displacement around the overpunch rather than digit visibility.

4. Ignoring Over Mintmarks

Everyone hunts overdates. But over mintmarks (like the 1875 S/CC) are just as cool and often cheaper.

Why Over Mintmarks Are Worth Your Time

• Same history – marks mint transitions
• Often rarer than date overdates
• Less competition from date-obsessed collectors
• Reveals mint logistics like die transfers

Good Targets to Start With

• 1875 S/CC (San Francisco over Carson City)
• 1906 O/S (New Orleans over San Francisco)
• 1942/1 Mercury Dime (both date and mintmark overdates)
• 1943 P/D/S (war nickels with multiple overpunches)

These fly under the radar because they don’t fit the “date over date” mold, but they’re minting anomalies worth your attention.

What to Do Instead: Broaden your search. When hunting overdates, specifically look for over mintmarks too. They’re often in the same collections and can be smart “sleeper” buys.

5. Trusting the Slab Too Much

A slab doesn’t guarantee correct attribution. I’ve seen plenty of mislabeled overdates in holders.

Slab Warning Signs

• No reverse photo (makes die verification impossible)
• Grading service that doesn’t specialize in varieties
• Attribution without specific die details
• Price way below market for the claimed variety

How to Verify

For any slabbed overdate, I check:

1. Population reports for that exact variety
2. Die details against reference photos
3. Serial number in the grading service’s database
4. High-res photos from the seller, even slabbed
5. Second opinion for expensive purchases

What to Do If It’s Wrong: Found an error? Most services will re-examine it. PCGS does this free if you provide good evidence. Keep photos, the slab, and your research.

6. Skipping the Story Behind the Coin

Overdates aren’t just minting errors – they’re history you can hold.

Why This Matters

• Provenance (like a 1942/1 dime from circulation) adds value
• History helps you appreciate the coin’s significance
• Personal stories make coins more desirable

Research I Do for Every Coin

For each overdate, I find out:

• Why it was created (war, die shortage, etc.)
• How many were made, how many survive
• Its history – famous collections it was in
• Market trends for that specific variety

What to Do If You’re Missing History: Got an overdate with no provenance? Try to trace it. Look for:

• Records from previous collections
• Matching toning that suggests shared storage
• Wear patterns that tell a circulation story

7. Paying Too Much for “Rarity”

The most expensive mistake? Overpaying because something’s “rare” without knowing the market.

Where Values Get Distorted

• Late-state overdates often sell below their rarity suggests
• Over mintmarks undervalued vs. date overdates
• Coins with minor flaws but clear overdates can be bargains
• Early 1800s dates often better value than 20th century

My Approach for New Collectors

Start smart:

1. Pick 2-3 overdate series to become expert in
2. Set price alerts on auction sites
3. Build relationships with variety-specialist dealers
4. Be patient – the right deal will come

What to Do If You Overpaid: Don’t panic. Many overdates appreciate. Join groups like CONECA or the Breen Society. Other collectors can help you understand your coin’s real value and find trading opportunities.

Your Overdate Success Strategy

Finding overdates is thrilling, but it needs a different mindset than regular collecting. Avoid these seven mistakes with a systematic approach:

1. Train your eye to spot real overdates vs. die doubling
2. Get proper photos for authentication and records
3. Study how your target varieties’ dies change
4. Include over mintmarks in your search
5. Verify slabbed coins with extra research
6. Research every overdate’s history
7. Know the market to avoid overpaying

Every overdate is a mint history lesson. That 1817/3 half dollar survived 200 years of circulation. That 1942/1 dime passed through countless hands before you found it. These coins connect us to the past.

By avoiding these common mistakes, you’re not just building a collection. You’re building expertise, making smarter buys, and joining a community that appreciates numismatics at its finest. Now get out there, and happy hunting!

Related Resources

You might also find these related articles helpful:

• Fix Any Over-dates Out There in 5 Minutes or Less (Quick Fix Guide) – Need to solve this fast? I’ve got a 5-minute method that works—every time. Whether you’re a serious collector or just fo…
• The Forgotten Art of Overdate Coins: Insider Secrets, Hidden Details, and Rare Finds That Most Collectors Miss – Let me take you behind the scenes of my decades-long hunt for overdate coins. When I started, I thought it was simple: f…
• I Tested Every Overdate Coin Identification Method — Here Are the Winners and Losers – I tested every overdate coin identification method out there—from grandpa’s “look close” trick to high-tech imaging. I s…