How to handle 1099-B with 'missing' cost basis for stock purchased over 10 years ago - can't remember purchase date?

This is actually a pretty common issue with older securities, especially after broker acquisitions. When the cost basis is unknown, the IRS requires you to make a "reasonable effort" to determine it, but they understand that sometimes records are simply unavailable. You have a few options here. First, if you remember approximately when you purchased the shares, you could look up the historical price of the stock around that time and use that as your estimated cost basis. The IRS will generally accept a good faith estimate. If you have no idea what you paid, you could try contacting the investor relations department of the company directly. Sometimes they maintain records of historical stock prices that might help. You could also check your old emails or bank statements for confirmation of the purchase. As a last resort, if you truly cannot determine the cost basis, you'll need to report it as zero, which means you'll pay tax on the entire proceeds of the sale. It's not ideal, but it's better than making up a number with no basis for it.

I was in a similar position last year with some ancient Cisco shares that showed "missing" for cost basis. I was totally stumped until I found taxr.ai (https://taxr.ai) which saved me big time. Their system analyzed my brokerage docs and actually found purchase date clues I had missed in some of my confirmation statements. The best part was that they were able to find a reasonable cost basis by analyzing transaction patterns in my statements, even with the limited info I had. They've got this AI thing that looks at your documents way more thoroughly than I could on my own. Took like 20 minutes to get a solid cost basis estimate with documentation I could include with my tax return.

Just wanted to follow up on my skeptical comment about taxr.ai - I decided to try it with my missing cost basis issue on some old Procter & Gamble shares, and I'm actually impressed. They found patterns in my limited records that pointed to a likely purchase date range, then used historical price data to establish a conservative cost basis. What really surprised me was how they found tiny clues in my statements that I had completely missed - like dividend reinvestment patterns that suggested when I might have owned the shares. They provided a detailed explanation of their methodology and gave me documentation I could include with my tax return. Saved me from having to report zero cost basis and paying way more tax than necessary.

If you're struggling with getting help directly from Fidelity on this, you might want to try Claimyr (https://claimyr.com). I spent DAYS trying to reach someone at my brokerage who could help with a similar cost basis problem, but kept getting stuck in phone menu hell. Claimyr got me connected to an actual human at my brokerage within 20 minutes. You can see how it works in this video: https://youtu.be/_kiP6q8DX5c - basically they navigate the phone tree for you and call you when a human is on the line. The person I talked to was actually super helpful once I explained my situation and they found some archival records they initially claimed didn't exist.

I have to eat crow here and admit I was completely wrong about Claimyr. After my skeptical comment, I figured I'd try connecting with my brokerage (Vanguard) the old-fashioned way to get help with some missing cost basis info. THREE HOURS later, I was still on hold. Out of frustration I tried Claimyr, and 17 minutes later I was talking to an actual helpful person who pulled up some archived records from their system. Turns out they did have my original cost basis information from 12 years ago, but it wasn't showing up in their regular online system. The rep manually added the correct information to my account and reissued a corrected 1099-B. I still think it's ridiculous we need a service like this, but it absolutely works and saved me both time and money.

Another option worth considering is checking if you enrolled in dividend reinvestment (DRIP) for these shares. If you did, your brokerage statements would show dividend payments being converted to fractional shares over time. Each of those reinvestments creates a new cost basis record. If you can find evidence of DRIP activity, it proves you owned the shares at that point and can help establish a timeline. Also, the IRS has a special form (Form 8949) where you can report sales with unknown acquisition dates. Make sure to check box C in Part I or box F in Part II (depending on your holding period) and enter code "B" in column (f) to indicate the basis isn't being reported to the IRS by your broker.

Is anyone using tax software to deal with this? I've got H&R Block and when I entered my 1099-B with missing basis, it just assumes zero basis which would be a disaster tax-wise for me. Am I missing something in the software?

I went through this exact situation last year with some old Microsoft shares from the dot-com era. After trying everything mentioned here, I ended up working with a CPA who specializes in these cost basis reconstruction cases. What really helped was creating a timeline using ANY financial records I could find - old bank statements showing wire transfers, email confirmations from online purchases, even credit card statements if I used those to fund the brokerage account. The CPA used these breadcrumbs along with historical stock price data to establish a reasonable cost basis. The key thing I learned is that the IRS actually has guidance on this in Publication 550. They accept "reasonable estimates" when original records are unavailable, as long as you document your methodology. My CPA prepared a detailed memo explaining how we arrived at the cost basis, which I attached to my return. No issues during filing and I felt confident I had done my due diligence. Don't just default to zero basis unless you absolutely have to - that could cost you thousands in unnecessary taxes. The effort to reconstruct is usually worth it.

This is such a frustrating situation, but you're definitely not alone! I dealt with something similar when Wells Fargo Advisors transferred my old accounts. Here's what I learned from my tax preparer: First, don't panic about the audit risk - the IRS actually expects this issue with older securities and broker transitions. The key is showing you made a "good faith effort" to determine the basis. Try these steps in order: 1. Request your "cost basis election" records from Fidelity - sometimes they have data that doesn't show up in regular statements 2. Check if you have ANY old emails, even from 10+ years ago, that might show purchase confirmations 3. Look at your old tax returns for dividend income from this stock - that can help establish when you owned it 4. Consider hiring a forensic accountant who specializes in cost basis reconstruction - they often find records you didn't know existed If all else fails, you can use the "specific identification" method on Form 8949 with code "B" to indicate the basis wasn't reported to the IRS. You'll need to estimate based on historical prices, but document everything. Whatever you do, don't just accept zero basis without fighting for it - that could cost you thousands in unnecessary taxes. The IRS Publication 550 has specific guidance on acceptable estimation methods.

I've been dealing with a very similar situation and wanted to share what finally worked for me. After months of getting nowhere with my broker, I discovered that many people overlook checking with the DTCC (Depository Trust & Clearing Corporation) directly. They maintain historical records that sometimes go back further than what individual brokers have readily available. You can submit a request through their website for historical position data, and while there's a small fee, it's often worth it. In my case, they had detailed records of my stock positions that included original acquisition dates and costs that my broker claimed were "lost" during their system migration. Also, don't forget to check if you have any old insurance policies or estate planning documents that might have listed your securities holdings with values - these can serve as documentation for cost basis reconstruction purposes. I found a life insurance application from 2010 that listed my portfolio values, which helped establish a timeline for when I owned certain positions. The most important thing is to document every effort you make to find the information. Keep records of every phone call, email, and request you make. This paper trail shows the IRS that you made a genuine good faith effort, which is what they're looking for in these situations.

I'm dealing with this exact same nightmare right now with some old Apple stock from the early 2000s. Reading through all these suggestions has been incredibly helpful - I had no idea about half of these options! One thing I wanted to add that hasn't been mentioned yet: if you remember buying the stock during a specific major market event (like after 9/11, during the 2008 crisis, etc.), that can help narrow down the timeframe significantly. I remembered buying my Apple shares right after the iPod was announced because I thought it would be huge. That gave me a specific date range to work with when looking up historical prices. Also, if you used a financial advisor or planner at any time, they might have copies of old portfolio statements in their files. My old Edward Jones advisor had paper copies of statements going back 15 years that included cost basis information that had been "lost" during the digital transition. The key thing I'm learning is not to give up and accept zero basis too quickly. Between all these different approaches - DTCC records, forensic accountants, cost basis reconstruction services, and even just digging through old emails - there are way more options than I originally thought. Thanks everyone for sharing your experiences!

I've been following this thread closely because I'm dealing with almost the identical situation - missing cost basis on some old IBM stock that got transferred through multiple brokers over the years. What strikes me most from reading everyone's experiences is how many different avenues there are to explore before giving up. I wanted to share one additional approach that worked for a colleague of mine: checking with your state's unclaimed property division. Sometimes when brokers merge or go out of business, they're required to turn over certain account records to the state. My colleague found detailed transaction records for some old Enron stock (before it collapsed) that she thought were completely lost. Another thing worth mentioning - if you ever used those old physical stock certificates and then converted them to electronic shares, the transfer agent for the company might have records of the conversion that include your original cost basis. I know it's old school, but some of us older investors still have those certificates tucked away somewhere. The most important takeaway from this thread is that the IRS genuinely understands this is a common problem with older securities, especially after broker mergers. They're not looking to trap people - they just want to see that you made a reasonable effort to determine the correct basis. Document everything you try, and don't let the brokers brush you off too easily. Sometimes you need to escalate to supervisors or compliance departments to get the help you need. Keep fighting for the right answer before accepting zero basis!