When opening the CSV file Excel assumes the phone number is a number and strips off leading zeros and "+" from +44 and turns it into something to the power 11, it seems to do this per number as a number with a space e.g. 01342 825392 converts OK. Setting the cells after import doesn't help. Libre Office is easier as you can set that field to text rather than standard in the import interface and then everything is good. I expect Excel has the same - somewhere.....
P.S. I felt that it is appropriate for you to have phone numbers and email addresses of the competitors as you could well have good reason to contact them during the event.
Just logging something to watch.
When opening the CSV file Excel assumes the phone number is a number and strips off leading zeros and "+" from +44 and turns it into something to the power 11, it seems to do this per number as a number with a space e.g. 01342 825392 converts OK. Setting the cells after import doesn't help. Libre Office is easier as you can set that field to text rather than standard in the import interface and then everything is good. I expect Excel has the same - somewhere.....
P.S. I felt that it is appropriate for you to have phone numbers and email addresses of the competitors as you could well have good reason to contact them during the event.