outside line prefix question

[lloyde6]

I have started getting a charge on my phone bill for a number I have never called and it is listed about 20 times this month.
My phone provider said it is coming from my house . After some investigating I found the number listed on my 311 receiver under the phone system menu under outside line prefix code.

Would this cause the receiver to call this number?

I have cleared the number out and set it to no prefix but I have to wait a few days till the phone company can tell me if it called out again.

Im not sure how the number got in there but I bought the receiver used a few years ago but only started having this problem last month.

If anyone could tell me if this would cause it to call out I would appreciate knowing so
I can be sure I have this problem solved.
Thanks

 

[vegassatellite]

I'm just venturing a guess here.

Perhaps someone put that number in before selling the box. If its some toll number like a 976 or something, maybe they put that in the box so that every time the box tried to call in, it would call that number first and they would get paid.