Advice on keyholding service

Hi, I work for a charity which has two premises, and we are thinking about getting a keyholding service so that staff don't have go out on their own if either of the burglar alarms goes off. We've not used one before - does anyone have any experience of this, or suggestions about what to look for when choosing a company to do this?

Thanks

We used Kings Security for a good few years, they were really good. You need to ensure that they are SIA registered and regulated.