Do we NEED separate HTTP and HTTPS sitemaps for corresponding GSC properties?

Question

We are in the midst of migrating from HTTP to HTTPS. According to Google Support, we need to have separate properties in GSC for each protocol. I also read that Google recommends that each property has a separate sitemap:

What URLs should our sitemaps list if we have redirects (from HTTP to HTTPS or the reverse)?

List all HTTP URLs in your HTTP sitemap, and all HTTPS URLs in your HTTPS sitemap, regardless of redirects when the user visits the page. Having pages listed in your sitemap regardless of redirects will help search engines discover the new URLs faster.

https://support.google.com/webmasters/answer/6033049

However, my company does not and will not have separate HTTP and HTTPS sitemaps. Does anyone know if this will cause issues and what those issues may be?

Answer 1

Its recommended to also use the http sitemap during the migration, but i have done migrations with and without and not noticed much difference.

You could say the migration might happen quicker as Google can still hit the http urls from the sitemap, where as if you change all the links on the site Google cannot hit them any more.

It's also usefull because you can monitor in Search console the amount of http urls still indexed vs what's in the sitemap.

However i can see the issue if your migrating your system and have to keep generating http sitemaps, might be extra development, but remember you only need the last sitemap before migration, you don't need to maintain it after.

So I'd suggest simply saving the old http sitemaps, then uploading the files to the https domain. Hard to see whats the issue here, just a few files on the server.