I’ve received a lovely Chinese Elm bonsai as a Christmas present and I’ve done research but I’m thing I can’t get concrete information about is the fertiliser that I should use and should the NPK change throughout the seasons. And can anyone suggest me some good fertiliser to use for this bonsai.

No fertiliser until spring. It is not growing in winter with lower temperatures and frosty conditions. You do have it out?

Are you in southern or northern hemisphere?

What do you mean out?

Northern hemisphere, United Kingdom Specifically

Out as in outside, where it belongs

No it’s indoors

Widymaj wrote:

No it’s indoors

Then place it outdoors, indoors it will die sooner or later ( and mostly sooner)

How come you’re so confident about that? I’m a beginner so I want to know some more information please

Why so confident?

Read up here: www.bonsaiempire.com/tree-species/chinese-elm

Placement: The Chinese elm thrives in either full sun and/or partial shade. In temperate climates, it can be left outdoors even during winter months. If you have an Chinese Elm Bonsai you can place it outside during the summer, but it's best to bring it into a cool, but frost-free, room in the winter. The Chinese Elm can usually endure some frost but it differs depending on the region it was imported from. Trees from northern Chinese regions are more frost-hardy than those coming from southern areas. Depending on winter temperatures Chinese Elms either drop their leaves or keep them until spring when the new shoots emerge.

So your in the UK, in a "temperate climate". So you can leave it outside.
When there is a lot of frost protect it. But when not freezing you can leave it outside.