Money

Inland Revenue

the tax folks

National Insurance

like Social Security, including the number

quid

a pound

"squid"

joking slang for a pound

dosh

money, cash

fiver,tenner

five- and ten-pound notes

old currency

not used any more but occasionally someone will refer to a florin (2 shillings = 10 p) or half-crown (5 shillings = 25 p). Also farthing, groat, guinea, crown ...