This needs to include all general client accounts held at the time you are completing this return.
Discrete client accounts are those held and used for one client only. A discrete account will usually incorporate the name of the client in the title.
In an auctioneering context, clients' money is the amount received from purchasers and held by the auctioneer on behalf of vendors, less any amount due to the auctioneer for commissions and costs incurred.
This usually occurs when both the firm of Chartered Surveyors and the client can withdraw funds from the account. The money held in such an account is not classed as clients' money.