The SIA registration, and re-registration every 3 years, is not concerned with financial issues, merely with any criminal offences disclosed, or if you have been detained under the Mental Health Act.
However many security employers use BS7858 screening which requires them to carry out a 5yr address and work history along with a credit check and a requirement for the employee to disclose any insolvency arrangements or County Court Judgements.
The good news is that any decision about whether this affects the employee's status, is up to the managment of the company. If they are satisfied that anything disclosed does not make the employee a risk then all they have to do is sign saying that they are happy and that's the job done. Also BS7858 checks are only done on commencement of employment.
Wordy details here
https://www.nsi.org.uk/wp-content/uploa ... o-0049.pdf
A final note: there is no published evidence, nor much anecdotal evidence to indicate that people in debt and more particularly people who have arrangements to deal with it, are an enhanced risk.
There are plenty of people who have ticked all the correct boxes and are utter liabilities though.....................!
Hope this is helpful, apologies for delay in posting.