You will of course pick the best one as the successful candidate, but the following points may be useful:
Explain to candidates when you let them know the outcome that although they were unsuccessful on the day for the particular job in question, you were impressed with their performance, and they were appointable.
Ask them if they would be happy for you to keep their names and contact details on file for any future opportunities in the next 6 months.
If, for any reason, your preferred candidate drops out at any stage, you can approach others who performed well at the selection procedure and offer them the job. This can even be the case after the preferred candidate starts work, if it happens in the very early stages. All this can apply up to a maximum of 6 months from the original interview date (It is acceptable to offer them the job in these circumstances if all members of the recruitment panel agree) – any longer than this and you should refer to your resourcing manager, as it may be better to start a fresh recruitment campaign.
If suitable opportunities arise at a later date, you may wish to alert the appointable candidates to the new vacancy. If you received approval for the new role (within 6 months) after the previous one and all the details of the post are the same (or so similar as to make no material difference) - location, grade, duties, hours - then the best candidate from the previous post can be offered the job, subject to the usual checks without the need for another interview.
You will need to ensure that you still comply with all the necessary processes of Safer Recruitment/Warner Recruitment if relevant. If a longer time span has elapsed or if there are significant differences with the post, then you can still contact the appointable candidates and invite them to apply, if you think the post would be of interest to them and they have the necessary skills. They will be treated the same as any other applicants at this stage and this should be made clear to them.
If the person is interested and wants to use the same application form without adding anything, you can email the recruitment team to add them to the new job using their original application form.
Please note that if there are internal candidates who have priority status for vacancies such as if they are individually at risk of redundancy and meet the essential criteria for the job or could do so with reasonable training, they must be given priority consideration before other appointable candidates as described above.