When you do call forwarding from your home phone to your cell, can the caller tell?

Maybe…
The typical home phone call forwarding is “call forward – no answer” (or “call forward – busy line”, but that’s not what you want), so the home phone will ring for some number of seconds, then the phone switch will redirect the call to your cell phone, which will ring until you pick up, or voice mail kicks in.

The transition from ringing your home phone to ringing your cell phone can be noticeable and will indicate to the caller that something was going on, if they are paying attention. If you have ring-back tones enabled on your cell phone, then the caller will definitely know since the ringing tone of the home phone would be replaced by your ring back tone.

You could test this yourself, once you get call forwarding set up, by calling the home phone from some other number (not your cell phone) and listening for that transition in ring sounds.

Your home phone service provider may offer a “forward all calls” option, in which case I don’t think that the home phone rings at all – the call is just redirected to the cell phone number. That would be smoother and less detectable.

Often, you can get a call forward package that includes the ability for you to choose what kind of forwarding you want, and to turn it on and off as needed.

There is a monthly charge for the call forward service on your home phone. There is no charge for the forwarded calls – - UNLESS the number you forward it to is a long distance number. In that case, then the charge is added to < > home phone bill. The caller never gets charged anything – regardless of where the call ends up.

You would have to talk to your local phone service provider to see what kind of services they offer and how much it costs.

If you are doing this to prevent anyone from knowing that you have left the house, then you will probably not be successful in the deception for very long – particularly if someone else is paying the bill for the home phone. In addition, the voice quality on a cell phone will probably be different than on the home phone, and answering the cell phone in any environment outside of the house will surely provide a different kind of background noise for the caller. Both of those things could be noticed by the caller.