Advice Cats Protection gives out when people think they have found a cat (some may be helpful to you).
If you have a cat living with you or visiting and think is either lost, abandoned, the owner has moved and left it behind, or appears to be just roaming around, sadly all too common and to think the cats/s was the result of someone’s so called good home, or you know of anyone else with such a cat DO NOT ASSUME IT HAS NO OWNER (OR ASSUME IT HAS), PLEASE REPORT IT TO AS MANY RESCUES AS POSSIBLE IMMEDIATELY (see:-
http://www.catchat.org/adoption/index.html) for some in your area.
EVEN IF IT LOOKS IN PERFECT HEALTH, PLEASE THINK HOW YOU WOULD FEEL IF YOU LOST YOUR CAT AND SOMEONE DID NOT BOTHER TO REPORT IT. It may simply be lost and could have been lost months previously. It is not unknown for cats to get into cars, removal vans, and so on, and be transported miles from their homes. Rescues have hundreds of cats on their lost/found register and the number increases on a daily basis. Most of the cats who go missing must be out there somewhere and, although we do manage to reunite quite a few with their owners, most of them are taken in or being fed by well meaning people, but are never actually reported. Depending on the condition of the cat and the safety of the location rescues can decide what course of action to take to ensure the cat receives all the help it needs. E.G. if the cat is well please your local rescues and ask them to check the lost list, take the cat to a vet to see if has been micro chipped.
If there is no record and the cat is well and not in a dangerous location perhaps you could on a long thin piece of paper write do I belong to you and your telephone number then attach the paper to a cat collar by wrapping sellotape round and round then put the collar on the cat if after 3 days you have received no reply take the collar off as many are considered dangerous and many cats have lost their life to them. Safer paper collars are available free from Cats Protection. Ring the local rescues and ask them to put the cat on the list waiting to come in. Please offer the cat shelter & feed it, I know some organizations say don't and they it will move on, however in our view that is callous, I am sure if you lost a pet it would be nice to think someone, somewhere was caring for it.
Also the cat has a greater chance of finding its owner or coming into care and finding a new permanent home, as it is not roaming from street to street looking for its next meal and endangering its life. If the cat appears below par please contact a local rescue immediately and ask if they will pay for the cat to be seen by a vet and if possible take the cat in.
So many people place a notice in a shop saying ‘FOUND’ etc, please remember that if the cat is going home even if only once a week as far as the owner is concerned they have not lost it so may not realise you are talking about their cat.
If the cat is timid and you cannot catch it most rescues have traps, at least then the little one can be taken to the vets to scan, have a MOT, flea and worm treatment etc, if unneutered Cats Protection can give vouchers for the cost. If feral you could ask rescues to try to find suitable homes for them. Although many cats people call feral are in fact what I call garden cats and that is cats that were once domesticated but then let down by society, these cats usually tame down very quickly once in a home.