@S H I think your concern is very valid, especially since you’re planning to distribute internationally through KDP and IngramSpark. Even though the UK publisher is in a different genre, I’d be a little cautious about choosing the name simply because it’s available in the US. I’d first look beyond whether another publisher is using the name and check whether they have a registered trademark, how established their brand is, and whether they are actively selling/distributing in markets where you plan to sell. The fact that they publish novels and you publish children’s books certainly reduces the possibility of confusion, but it doesn’t automatically eliminate it. I also wouldn’t choose the second name solely because it’s “safer” if you genuinely dislike it. Your imprint is something you may want to build for years, so I think it’s worth doing a proper clearance search on your favorite name first. If there are no significant conflicts, you may decide the name is worth keeping; if there are, you’ll at least know before investing heavily in the brand. Have you already checked the favorite name against UK and US trademark databases, or have you only searched for other publishers using the name?