Hi Mike.
Sadly, I have to agree with you that it is becoming more like Rip-off Britain.
As a short-term measure, I can only suggest that it may be cheaper for your son to call you. It is worth him checking the calling rate from his phone in his room.
You've probably seen other institutions on this site which have similar systems. In some cases we have discovered the geographical prefix under the 0870.
Looking at
Numbers administered by Ofcom, the UK regulator, we see that 0870 147 is operated by Torch Communications (see 'Special services 08').
The list (see 'Geographic numbers: Code blocks 2000 00 to...') with 020 (London) numbers on shows that Torch have the following prefixes. The dates are given by Ofcom as when they were last changed:
Prefix | | Last changed |
020 1174 | | 03/2002 |
020 7160 | | 07/2003 |
020 7788 | | 05/1999 |
020 8181 | | 06/2001 |
I presume that the above number is a direct dial to your son's room. If this is the case, I suggest you '****' the last 4 digits. If not, is it a number which you dial and then dial the extension you require? In this case, we may find the needle in the haystack before we find the number we're after!
If it is a direct number, I suggest you take the last 4 digits of the 0870 and put them onto the geographical prefixes I have given above.
The first one may not work as it is 'national dialing only'. That is, the number begins 1 and must be dialed with the 020 dialing code, even from within that area code. BT and other operators seem to block these numbers, as they are intended for using with non-geographical numbers.
In some cases, these systems use VoIP (voice over IP), which routes the calls over the internet. These lines will probably not have an alternative to the 0870.