if you have a accident,the parties involved notify their ins company,you tell them what happened,who was to blame etc,etc,then the insurance companies talk to each other to sort it out either way,the cars gets repaired,if it was your fault you lose some ncb,unless its protected,or if it was the other parties fault,you dont,but it will still count against you in the next few yrs.thats about it.
But if the accident was your fault and you only have Third Party, Fire and Theft insurance, you will be liable to pay for your own repairs. The insurance will only cover repairs to the third party.