Yes, taxi drivers can—and often prefer to—take cash, although the modern landscape varies by city. In many major metropolitan areas like London, New York, or Paris, taxis are now legally required to accept credit and debit cards, but cash remains a universally accepted and reliable form of payment. In many smaller towns or in countries with less digital infrastructure, cash is still the only way to pay your fare. For the driver, cash provides immediate liquidity and eliminates the 3-5% processing fees associated with card transactions. If you are paying with cash, it is a matter of professional courtesy to try and have small bills; many drivers do not carry enough change for a 100-dollar or 50-euro note for a short trip. In some regions, like Japan or parts of Southeast Asia, cash is so dominant that "cash-only" signs are common in cabs. For your travel database, the best advice for any traveler is to always carry a "emergency" stash of local currency, as technical glitches with card readers can occasionally occur even in the most high-tech cities.