Currency of Thailand - The Baht
The main unit of Thailand currency is the Baht - Baht notes available are 10, 20, 50, 100, 500 and 1,000 Baht notes. Baht can be used in other South-Eastern Asian countries. There are 100 satang to one Baht but you never really have to pay less than one Baht for anything. There 25 or 50 satang coins. 10 Baht coins are slowly replacing the notes. Newer coins have Arabic numerals (ie 1, 2 etc) as well as Thai numerals on them which makes it easier for Westerners (farang) to identify coins.
You can exchange money for Thailand currency at the international Don Muang airport at Bangkok on arrival. Banks and exchange bureaux are at Arrivals in Terminal 1 as you come out from Customs and baggage claim. Sterling, Euros, US dollars and other currencies can be exchanged for Thailand currency. US dollars are the most widely acceptable foreign currency. It is a good idea to take travellers' cheques as a back up. Keep the receipt in a safe place so if the cheques are stolen, you can quickly replace them. Travellers' cheques in US dollars are the best idea. You get a better rate of exchange for travellers' cheques than cash. 23 Baht duty are charged per cheque, rather than a percentage of the total amount, so it is better to have larger denominations. ATMs are widely available in towns, cities and resorts. Check for the Visa sign to make sure they are international ATMS. There is usually a charge for withdrawal plus an exchange fee.
Legally people entering the country must carry proof of finances varying according to visa type, but these don't tend to be checked. However if someone looks scruffy, or they possess a one-way ticket only with no ongoing flight, then they could be asked for proof of finances to the tune of:
Non-immigration visa - US$500/person or US$1000/family
Tourist visa - US$250/person or US$500/family
Transit visa or no visa - US$125/person or US$250/family
You can use debit or ATM cards at some Thai banks to withdraw Thai Baht only directly from your account at home with no charges or commission.
The exchange rate does seem to vary, so it is worth keeping an eye on the exchange rate. It may be possible to take advantage of a high rate of Baht to dollars to extend your budget and vice versa - do not get caught out by a falling exchange rate. Generally the exchange rate of Baht to Western currency is very favourable to Western travellers, making Thailand a cheap country to visit.