Separate Domains vs. Subdomains for Local SEO?

New client here, focused entirely on local SEO. They currently run 3 separate domains, each one tied to a related but distinct business service—like Carpet Cleaning, Rug Cleaning, Duct Cleaning, Concrete Cleaning, and so on. Over time, every time they added a new division, they went ahead and created a new site with its own domain. Some of these domains have more traffic than others, mostly based on how old they are.

I’ve just been brought on to handle their Local SEO and also to rebuild their sites. They’ve been spending a lot on Google Ads every month, so we’re looking to optimize for organic results. My main question: should we keep these as separate domains, or consolidate everything into subdomains or subdirectories under one main site?

Would love to hear your experiences and suggestions!

I’d definitely suggest going with subdirectories under one main domain. This way, you consolidate all your link authority, and your main site benefits from having all the inbound links in one place. Make sure to vary the content, optimize titles and meta tags, and include local SEO elements like Google Maps plugins or addresses.

If these are separate services and almost like different businesses, it might be better to keep them as individual sites. Grouping everything on one domain could dilute the main topic and make it harder to rank for specific keywords. I’ve seen cases where combining topics led to a loss of rankings, and separating them brought everything back. You might want to add ‘service area’ and ‘location’ pages for each site to improve local reach.

Subdomains are treated like separate sites by search engines, so consolidating everything as subdomains would probably be the least effective choice. Subdirectories or keeping them as individual domains would be better options.

If these are older, well-established domains, it might be best to keep them separate. Merging everything into a single domain could lead to complications and a drop in rankings during the transition. If you’re redesigning the sites, be aware that there could be a temporary drop as Google reassesses everything, which could take anywhere from a few days to a couple of weeks.