Dear Jane,

It would be a sin if you received Communion with serious sin on your soul without having gone to Confession beforehand to have it absolved. It would be fitting to go to Confession before Confirmation, especially if there is mortal sin to confess.

With Confirmation one is confirming the covenant made in your name by your godparents and parents.

It would only make sense that you would want to make this profound promise to God with a clean soul, however, as a rule, it is not necessarily a sin to receive Confirmation without first going to Confession.

Peace,

Paul