Can an iPhone be used if it's been deactivated?

Mine was lost so I deactivated it. Before it was deactivated the person left a message saying they found it and said they handed it in to the bar staff in the pub it was lost. When I arrived the staff said they knew nothing about it. I assume the person who said they would hand it in had kept it. Is it possible the taker could still use the phone even though it's been deactivated. Are their ways they can get round it? My contract provider did the deactivating etc.

Yes it can be used just like a ipod would be used

If you deactivate it then you need apple or your provider to open it again. Unless it is before the iPhone 5 came out then he can simp ally hold down both boutons at the same time for a minuet and factory reset it. In the newer apple products you need to use your apple ID to reset it. So sad that you lost your phone.

If it is similar to the US, lost/stolen phones are blacklisted. Meaning they can never be reactivated in the UK ever again. They can use as an iPod but if you're iCloud is still on the device odds are if they ship and spirit away on the black market, it won't work there either. Remote wipe your data if iCloud was activated to be certain. At best, it'll be an iPod in Algeria somewhere. Best luck.