Claudia, You'd have to have a lock smith make all those locks fit the same key. If they are all from the same manufacturer, it might work, but it won't be cheap. If they are of different makers, it is probably not possible.
If you have a lock smith locally, try taking the keys in and see if they can tell you what can be done. We have the same situation nearly, it is a pain, but I believe I found it would cost $35.00 per lock to match them <OUCH> Tom Fowle
