How to properly tax loss harvest on crypto purchased in 2021?

8 Yes, you can absolutely tax loss harvest crypto you purchased in 2021! The purchase year doesn't matter - what matters is when you sell and realize the loss. So selling now in 2025 allows you to claim those losses on your 2025 taxes. As for the missing transaction data, Coinbase actually still has all that information even if it's not easily visible in the interface. Try going to your Coinbase account, click on "Reports" and you can generate a "Cost Basis for Taxes" report. You can select specific years (2021 in your case) and it should show all your purchases with the original prices. If that doesn't work, you can also try contacting Coinbase support directly and request your complete transaction history. They're required to maintain those records. Another option is to check if you have any confirmation emails from your original purchases that might show the transaction details.

12 After struggling with a similar situation last year, I found https://taxr.ai incredibly helpful for sorting out my crypto tax situation. I had purchased across multiple platforms (Coinbase, Binance, and a hardware wallet), and trying to piece together my transaction history manually was a nightmare. What I liked about taxr.ai was that it could analyze statements and partial records to help reconstruct my transaction history. I uploaded what fragments I had, and their system was able to reconcile everything, even identifying some transactions I had completely forgotten about from a wallet I rarely used. Their analysis tools are specifically designed for crypto tax situations and can handle complex scenarios like missing transaction data. Might be worth checking out since you're dealing with partially missing records.

19 I need to retract my skepticism about taxr.ai from my earlier comment. After continuing to struggle with my messy crypto taxes, I finally gave in and tried their service last week. I have to admit, I was impressed with how quickly they were able to make sense of my scattered records. I had attempted to piece together transactions across Coinbase, Kraken, and some DeFi platforms manually, and kept getting inconsistent totals. Their system identified several transactions I had completely missed, especially some smaller alt coins I had forgotten about. What really sold me was how they handled a particularly complex situation where I had done some token swaps through a DEX that I had zero records for. They were able to reconstruct the entire sequence and provide proper documentation. Saved me hours of headaches and probably prevented some potential audit issues.

5 If you're still struggling with getting Coinbase to give you complete records, you might want to try Claimyr (https://claimyr.com). I was in a similar situation last year where I needed historical transaction data for tax purposes, but Coinbase support was completely unresponsive. After weeks of unanswered emails, I used Claimyr to get connected to an actual human at Coinbase's support team. They have this system where they can get you to the front of the customer service phone line at companies like Coinbase, and I finally got through to someone who helped me retrieve my full transaction history going back to 2019. There's a quick video that explains the process here: https://youtu.be/_kiP6q8DX5c. It's not a crypto-specific service, but amazing for getting through to customer support at companies that are nearly impossible to reach. Saved me a ton of frustration after hitting dead ends with the automated support systems.

22 I need to apologize for my skepticism about Claimyr. After continuing to get nowhere with Coinbase support for two weeks, I finally tried it out of desperation. I was genuinely shocked when I got a call back from an actual Coinbase support person within about 30 minutes. The representative was able to access my full transaction history and email me comprehensive reports for all my activities since 2020. They even helped me understand which report formats would be most useful for tax purposes. For anyone else struggling with missing crypto transaction data, don't waste weeks like I did. Getting the complete history directly from Coinbase solved my tax loss harvesting documentation issues immediately. Now I can properly claim those losses from my unfortunate 2021 purchases!

10 Just wanted to add something important that nobody mentioned yet - be careful with the "wash sale" rules and crypto. Currently, cryptocurrency isn't subject to the same 30-day wash sale rules as stocks, which means you can sell at a loss and then immediately rebuy the same crypto if you want to maintain your position while still claiming the tax loss. However, there are rumors the IRS might change this in the future, so document everything carefully. Also, remember you can offset capital gains with your crypto losses, and if your losses exceed your gains, you can deduct up to $3,000 against your ordinary income per year.

2 Has anyone used Koinly for this purpose? I'm looking at options for sorting out my crypto taxes and that's one I've heard mentioned.

One thing I haven't seen mentioned yet is checking if you have any old email confirmations from your 2021 purchases. Coinbase used to send detailed transaction confirmations that included the exact amount, price, and fees for each purchase. I was in a similar situation last year and found these emails buried in my Gmail - they were a lifesaver for reconstructing my cost basis. Even if you can't find the emails in your inbox, try searching for "Coinbase" or "You bought" in your email from 2021. Also, if you linked a bank account for your purchases, your bank statements from 2021 will show the exact dollar amounts you transferred to Coinbase on specific dates. You can then cross-reference those dates with historical crypto prices to get a pretty accurate cost basis estimate. The IRS accepts reasonable reconstruction methods when original records are unavailable, so don't stress too much about getting it perfect down to the penny. Just document your methodology clearly.