Call waiting is another paid service which can be enabled or disabled faster with a few codes. Dial *#43# and again punch “call”. This will tell you the status of the call waiting. If you want to enable it on type *43# and ‘call’. To turn it off type #43# and “call”.
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Seems that the codes hidden in your iPhone aren’t really easy to remember but with constant use it’ll be etched in memory just like a frequently used number. Call forwarding uses a fairly simple code *#21#.
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