Costs are easier to compare once you know where repeat charges usually appear. The main pressure points are card issuance fees, foreign spend costs, ATM withdrawal fees, conversion spreads, and physical card shipping costs.
Each one looks small in isolation. A card that takes 1.5% on FX and 2% at the ATM can easily eat the entire month's cashback before it posts. The fee structure also signals how the issuer makes money. Cards that look “free” at signup often recover the cost through wider spreads at checkout.
Here is how each card stacks up across the same fee categories.
Uphold Card
- Annual or monthly fee: £0
- Foreign transaction fee: 0%
- ATM cost: £2.50 in the UK, £3.50 abroad
- Conversion spread: Standard trading fees when spending crypto, plus FX conversion outside GBP, EUR, or USD
- Physical card and shipping: Virtual card free, physical card £9.95 shipping
KAST Card
- Annual or monthly fee: $0; first two virtual cards free, extra virtual cards $2 each, some countries charge $2 for the first virtual card
- Foreign transaction fee: 0.5% to 1.75% on non-USD spend
- ATM cost: $3 plus 2% per withdrawal, plus FX on non-USD ATM use
- Conversion spread: 0% on USD card spend; non-USD spend takes FX fees
- Physical card and shipping: Physical card fee removed; $40 shipping
Nexo Card
- Annual or monthly fee: £0
- Foreign transaction fee: 0.2% on weekdays, 0.7% on weekends in the UK, EEA, and Switzerland
- ATM cost: Free monthly allowance by tier up to £1,800, then 2% with £1.99 minimum
- Conversion spread: No separate card spread line disclosed; FX fees and Credit Mode borrowing cost apply
- Physical card and shipping: Shipping free, but physical orders are temporarily paused
Coinbase Visa Debit Card
- Annual or monthly fee: £0
- Foreign transaction fee: No separate fee disclosed in UK help pages
- ATM cost: No Coinbase ATM fee; ATM operator may still charge
- Conversion spread: No card spend fee, but crypto conversions include Coinbase spread
- Physical card and shipping: No application fee or credit check
RedotPay
- Annual or monthly fee: $10 virtual card issuance fee; $0 annual fee
- Foreign transaction fee: Purchase FX terms not clearly disclosed; ATM transactions in other currencies add 1.2%
- ATM cost: USD card ATM withdrawals are 2% up to $10,000 monthly, then 3%
- Conversion spread: ATM withdrawals add 1% crypto conversion; purchase conversion pricing is not shown as one simple spread line
- Physical card and shipping: $100 one-time issuance fee for the physical card
The cheapest-looking card is not always the cheapest to use. If you travel often, compare the international travel cards shortlist before deciding.
Worked Example: Spending £500 a Month in the UK and Abroad
Picture a UK user spending £400 on groceries and online shopping at home, £100 on a weekend trip to Spain, and pulling out £100 from a UK ATM. Here is how each card would treat that month.
- Uphold Card: £400 of GBP-balance spend earns £4 cashback at 1%. The £100 in Spain has no foreign transaction fee. The ATM withdrawal costs £2.50. Net cost is roughly £2.50 minus the £4 reward, leaving a small gain.
- KAST Card: £400 spent from a stablecoin balance earns 1% in KAST Points (worth $4 in points value, not cash). The €100 spend in Spain triggers a 0.5% to 1.75% non-USD FX fee, costing roughly £0.50 to £1.75. The ATM withdrawal costs around $3 plus 2%, or about £4 total. Out-of-pocket cost is around £5, with rewards paid in points.
- Nexo Card: No UK cashback applies. The £400 home spend is free. The £100 Spain trip on a weekday adds 0.2% FX, or £0.20. The ATM withdrawal stays inside the free tier allowance. Net cost is around £0.20.
- Coinbase Visa Debit Card: GBP-funded spend has no card fee. Any crypto-to-GBP conversion before spending includes Coinbase spread. Monthly offer-led rewards depend on the active campaign rather than a flat rate, so the figure varies.
- RedotPay: Spending £400 from a stablecoin balance has no flat cashback. The £100 abroad faces the 1.5% merchant fee in some categories (£1.50). The £100 ATM withdrawal costs 2% plus 1% crypto conversion, or about £3. Net cost is around £4.50.
Across this scenario, Uphold is the only card where rewards exceed costs for a typical UK month. The cashback is paid in GBP. The FX fee on the Spain spend is zero. Nexo is the cheapest if you do not need rewards at all. The weekday FX rate is low and the ATM allowance covers most users without extra charges. KAST and RedotPay only make sense if your balance already lives in stablecoins. For any UK user who has to fund through a GBP transfer first, the FX, ATM, and conversion fees stack up fast.