You must personally make a request to use the discount voucher and cannot revoke this request once it has been made. The discount voucher can only be used once, cannot be split, does not entitle the bearer to change and cannot be converted into cash. In order to use the full value of the discount voucher, you must always purchase goods of a higher value than that indicated on the voucher.
The total spent using the discount voucher does not entitle the bearer to accumulate points for said amount (e.g. on a purchase of £15 partially paid with a discount voucher for £ 10: no points will be due for the £10 paid with the voucher. Instead, points will be due for the £ 5 paid with the other forms of payment used in store or online).