Morning

Could someone please confirm if existing store room doors require just signage, or should they be compliant with regard gaps, strips, seals and closers as per the main fire doors.

Thank you

What signage? If you are talking fire door signs then they must be to fire door standard and not just normal doors if you are signing them this way.

Your FRA, if carried out by a competent person, will detail which doors need to be fire doors, with closers or kept locked shut, and to what standard they need to be (notional, upgraded or current FD30/FD30S/FD60/FD60S standard)

By signage I was referring to 'Fire Door Keep Locked Shut' signs.

The FRA which the client has had completed, doesn't refer to each individual door

If it's a cupboard/store then you can omit closers and mark fire door keep locked shut. It would need to be FD30 (intumescent strips) unless protecting an escape route in which case it would need to be FD30S (strips and cold smoke seals). An existing notional fire door with no strips or seals and 25mm stops may be acceptable, but the FRA must indicate why this is so.

This assumes that the location and contents of the room even need to be of fire resisting construction and doors in the first place, whilst desirable for property protection it's not always a legal necessity for life safety.