The Crypto Records to Keep Before Tax Time

Tax rules for cryptoassets are set country by country and change often, so nothing here is advice about what you owe. What does travel between jurisdictions is the record-keeping. Whatever your rules turn out to be, they will be applied to a history of transactions — and that history is far easier to assemble while it is happening than to reconstruct two years later from a venue that has since closed your account.

Assume more events count than you expect

Most systems treat a disposal as the event that matters, and a disposal is usually more than selling for cash. Swapping one token for another, spending crypto on something, and in many places receiving it as income — staking rewards, airdrops, payment for work — are each events with a value at the moment they happened. Moving your own coin between your own wallets normally is not, though the fee paid to move it may be. The practical consequence is that an active year in DeFi can generate several hundred events out of a handful of decisions.

Four fields, captured at the time

A usable record of any event carries the date and time, what went out and what came in with amounts, the value in your own currency at that moment, and the fee. The third is the one that cannot be recovered later with much confidence: a daily closing price is easy to look up, a price at 14:07 on a pair that moved eight per cent that afternoon is not. Export from every venue you use at least once a year and keep the raw file rather than a screenshot of it.

The records vanish from the places you assume are permanent

Exchange histories are not archives. Venues delist pairs, retire old APIs, cap exports to the last twelve months, close accounts in markets they withdraw from, and occasionally stop existing — customers of the collapses in our failure record lost their transaction histories along with their balances. Anything that exists only inside an account you do not control is a record you are borrowing. That includes the venues currently in good standing on our graded list.

Cost basis is a method, not a number

When you sell part of a holding accumulated over many purchases, something has to decide which units you sold. Jurisdictions differ on which methods they allow and on whether you may change method later. That choice, applied consistently across every disposal, is what turns a pile of transactions into a gain or a loss. It is also why an average entry price from a position calculator is a useful sanity check on your own numbers and not a figure to file.

When to stop and ask someone

Bring in a professional when the answer depends on facts rather than arithmetic: income received in crypto, mining or staking at any scale, losses from a failed venue or a theft, a move between countries during the year, or anything held through a business. Bring the exports rather than your conclusions — the conclusions are the part they are being paid for.