CGT filing when there is no tax liability

We have just sold a property that we had lived in for the majority of time we owned it, I have calculated that there is zero tax liability and we aren't registered for self-assessment. Do we still need to make a submission with 60-days of the sale or should I just keep the calculations from the HMRC website in case it needs to be reviewed in future for some reason? Most websites including HMRC say that we don't need to file but I wanted to double check. I've bee trying to get through the HMRC on phone lines for a few days but it seems that they're experiencing some problems. Thanks

Hi,
If you are UK residents and the disposal of this property does not result in a capital gain liability, there is nothing to declare. You can keep a copy of your calculation, to support your decisions that no tax is payable.
Thank you.

Thanks for confirming