To make a donation in this way, you have to instruct your employer to deduct regular charitable donations from your pay which are then forwarded to the chosen charity via an Inland Revenue approved Payroll Giving Agency. This takes place before tax, which means that you are given tax relief on your donation at whatever rate of tax you pay. Many companies will match fund any donations made this way by their employees, so the value of your donation may be increased. Do ask your employer if they are able to do this.