Pruning citrus trees is recommended after harvest.
Pruning citrus trees is a preference and not a necessity: if you have space constraints or prefer them to stay manicured, then prune after harvest. You can prune back the foliage to your liking or simply tip them a little to encourage new growth.
However, if you’re getting suckers or growth at the grafted portion (bottom portion of your citrus tree) cut them off right away, as these suckers will create sour fruit.