Kerry
Well done, its certainly changed since I was there. The Gov.UK website is good too:
"Money
ATMs are available in Lusaka and some major towns, but tend to only accept Visa and not Mastercard. Major credit cards are increasingly accepted by larger shops, hotels, restaurants and tour operators. Many companies charge a 5% fee for the use of credit cards. Make sure credit cards are swiped no more than necessary and that all carbons are destroyed. Only use reputable banks and bureaux de change to exchange money or use ATMs as counterfeit US$100 and Zambian Kwacha 50 notes are in circulation.
Since May 2012 all transactions taking place within Zambia must be carried out in the local (Kwacha) currency. While foreign currency can still be exchanged in Zambia, it is against the law to quote, pay or demand to be paid or receive foreign currency as legal tender for goods, services or any other domestic transaction. Doing so can result in a fine or a 10 year prison sentence.
In August 2012, the government approved the Bank of Zambia’s proposal to rebase the Kwacha. The new currency was introduced on 1 January 2013 using a rate of 1000 old Kwacha = 1 new Kwacha. Old Kwacha will remain legal tender until 30 June 2013."
Have a good trip.
Sylvia