I have a 200 amp service in my house they recommend to add 50 amp more to be safe . Because I put a large addition on . I have 4.0 copper coming in to my box .from the weather head .

Are you sure you have copper from the weatherhead? I haven't seen that for 40 +years. To get 250 Amps you will need to change the box as the main breaker is rated @200 Amps.

Hi,

Lets start with a definition from you please. Who is they?

Yes i am sure it has copper wire.. can i run a sub panel from the meater box for the extra 50 amps..

Please do me a favor and do not use all caps if it can be avoided. Thanks.

In answer to your question, yes 50 amps can be pulled from the 200 amp panel to feed a subpanel.

My concern is that you have provided no information on the load to be serviced in this large addition. What is in this addition? Have you had an electrician do a calculated load for the entire residence yet?

The only method to "add a extra 50 amps to my existing 200 amp service" is to change the entire service entrance, to include the conduit, wiring, and metering to a 320 amp service entrance.

Done properly, but depending on several conditions, you may be able to leave the existing 200 amp panel and add a second 200 amp panel, or less, once the new 320 amp service entrance is installed.

You may, as Don mentions, add a 50 amp subpanel fed by a 50 amp branch circuit breaker into your existing 200 amp panelboard. This assumes your existing 200 amp service has the capacity for this added load. The new subpanel cannot be simply fed by your meter box.

Before this is done, a service rating local calculation must be done by a qualified electrician. Then the electrician must consult with the power utility to see if they can serve this added load.