Missing October 15 costs extended crypto filers 5% of unpaid tax a month

For anyone who paid in full in April, October 15 is a paperwork date. The failure-to-file penalty is 5% of unpaid tax per month ^[4], so a filer whose April payment covered the bill faces that percentage on a balance of zero ^[15]. Everyone else pays for the date. Each $1,000 left unpaid costs $50 a month in that penalty. The cap is $250, reached after five months, which for a return due October 15 is mid-March 2027 ^[11][14]. That comes on top of the interest and late-payment charges that will have run on the same balance for about six months by the deadline ^[13]. A minimum penalty also applies after 60 days, though the source does not give its amount ^[5].

Form 1099-DA is new this year. Brokers have begun reporting 2025 transactions on it, and Crowdfund Insider reports that this gives many taxpayers a proceeds figure to match against their own records even when cost basis is still incomplete ^[3]. Proceeds are only half of a gain. The other half is what the coins cost, and that is where the hours go: the same report says cost-basis tracking across self-custodial wallets and multiple venues remains complex ^[6].

An extended filer has about two weeks left, and they can go a few ways. In the dull case the records reconcile to the 1099-DA, the return goes in, and the only cost is interest on any April shortfall ^[2]. In the harder case the filer has proceeds on the form and gaps in basis, and has to reconstruct older lots and separate capital trades from ordinary income such as staking rewards in the time left ^[8][9]. In the worst case the filer misses, pays the monthly penalty, and, according to the source, raises the chance of closer review where digital assets are involved ^[4][16].

I think this deadline's cost falls almost entirely on people who underpaid in April, and it scales with how much they underpaid ^[15][11]. The counter-case is that the penalty is the smaller risk. On that view the bigger one is a return filed on time with figures that do not line up with the broker's proceeds. The report does not say how often that happens, or how many extended crypto filers paid in full in spring. If most of them did, October 15 costs this group little beyond the hours spent reconciling. That would make my view wrong in practice even if the penalty figures are right.

The CLARITY Act's failure leaves the tax calendar where it was. The Senate vote on the Digital Asset Market CLARITY Act in mid-September went 49-50, 11 short of the 60 needed to proceed ^[7][12]. The SEC and CFTC have said they will keep writing rules on trading, custody and related topics without waiting for Congress ^[10]. According to the report, legislation may resume after the election cycle, and compliance obligations already run on the calendar long used for other asset classes ^[17].