Wallets like CoinOS calculate price basis in fiat at time of incoming transfer + expenditure. You can then export this as a CSV to a calculator/tax app like Koinly, which can figure out the total amount of capital gain/loss (if any occurred) on the entirety of a given period's history. It is an extra step or two but it's do-able - and definitely easier if you are a contractor/proprietorship vs employee.
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Thanks so much for the reply! I have been trying to convince my employer of the value of starting to accept Bitcoin and make it part of the corporate treasury as a means to combat inflation, but the learning curve is too steep for him to get comfortable with it in the 5 milliseconds of free time he has every day.