Using a mobile phone
In the event of an officer making an error with the ticket by putting the wrong house number (i.e. 50 rather than 05) and the fiscal compounding that error by sending a summons to the address on the ticket. Is the ticket invalid ?
Once proceedings are issued then the ticket becomes irrelevant. The only issue that the court will be interested in is whether or not the officer can prove beyond reasonable doubt that you were using a phone whilst driving.
A defect on the ticket is not a defence I’m afraid. The court will accept that it was simply a mistake.
Have you got any penalty points already? If so, how many?