The big misconception: “I swapped to USDT, so I've safely cashed out — no tax yet”
The reasoning feels airtight: no fiat hit the bank account, so nothing was “realised”, so no tax — park the profits in USDT and relax. It is precisely backwards. In the UK, Australia and the US, exchanging one cryptoasset for another — a stablecoin very much included — is itself a disposal. The gain on the coin you swapped away crystallised the moment you swapped it, at that moment’s market value.
If one page on this site saves a reader from an unpleasant letter, it is probably this one.
Why the swap counts
Tax law asks “what did you dispose of?”, not “did fiat arrive?”. Swap one appreciated BTC into 60,000 USDT and, for tax purposes, you sold that BTC at roughly 60,000 — a capital gain against your original cost — and then “bought” 60,000 USDT with the proceeds.
- The taxable leg is the BTC, not the USDT.
- The USDT barely moves in price, so it rarely produces gains of its own — but its acquisition cost (about 60,000) becomes the starting point for whatever you buy with it later.
- So “BTC → USDT → buy the ETH dip” is, in the UK, Australia and the US, usually two disposals: the BTC settles first, then the USDT settles when it buys the ETH — the second typically near zero, but still an event with a date and a value that belongs in your records.
Four-country table
| Operation | UK / AU / US | Germany |
|---|---|---|
| Buy stablecoins with fiat and hold | Usually not taxable | Not taxable |
| Coin → stablecoin (BTC → USDT) | Disposal — the outgoing coin settles | Depends on the one-year clock |
| Stablecoin → another coin (USDT → ETH) | Disposal (the stablecoin leg, gain ≈ 0) | Private-sales framework |
| Spend / pay with stablecoins | Treated as a disposal | Holding period decides |
| Earn yield on stablecoins | Interest taxed as income | Other income |
Two things people overlook: yield and depegs
- Stablecoin yield: returns from parking USDT/USDC in an earn product or a DeFi protocol are, in most countries, income at market value on receipt — the same logic as staking rewards (Germany books it as other income).
- Depeg losses: “stable” is a design goal, not a law of nature — there have been prominent breaks. If a stablecoin you hold falls hard and you dispose of it, that loss is normally a capital loss, offsettable under your country’s rules. Whether and how, in Losses, theft and collapses.
The leg nobody records
Because stablecoin legs look like “nothing happened”, they are the transactions most often missing entirely from people’s records — and without them, you cannot show when, or at what value, that BTC was actually disposed of. Record every swap that touches a stablecoin: date, tokens and amounts each way, fiat market value at the time. The full scheme is in Keeping transaction records.
FAQ
I parked my profits in USDT and never withdrew. Tax, really?
If I only ever move through USDT and never touch fiat, is there no tax?
Is interest earned on stablecoins taxable?
Official sources
- UK: HMRC, Cryptoassets Manual — gov.uk/hmrc-internal-manuals/cryptoassets-manual
- Australia: ATO, Transactions — acquiring and disposing of crypto assets — ato.gov.au/…/transactions
- US: IRS, Digital assets — irs.gov/filing/digital-assets
- Germany: BMF letter on cryptoassets (updated 2025) — bundesfinanzministerium.de
Checked against the official pages on 1 September 2026. Stablecoins evolve under the same guidance as other cryptoassets; the authorities’ publications govern.
The stablecoin trap is that nothing seems wrong
Precisely because the price barely moves, the stablecoin legs go unrecorded — and only at reconciliation time does it emerge that the real disposal moments cannot be reconstructed. This page is not tax, legal or investment advice for your situation; stablecoins in DeFi, cross-border payments or large transfers get more complicated than anything here, and deserve a licensed professional’s eyes.