Client wants to remove mobile URLs from their sitemap to avoid indexing issues. However this will require SEVERAL billing hours. Is having both mobile/desktop URLs in a sitemap really that detrimental to search indexing?

[RosemaryB]

We had an enterprise client ask to remove mobile URLs from their sitemaps.  For their website both desktop & mobile URLs are combined into one sitemap.  Their website has a mobile template (not a responsive website) and is configured properly via Google's "separate URL" guidelines. 

Our client is referencing a statement made from John Mueller that having both mobile & desktop sitemaps can be problematic for indexing.  Here is the article https://www.seroundtable.com/google-mobile-sitemaps-20137.html 
We would be happy to remove the mobile URLs from their sitemap.  However this will unfortunately take several billing hours for our development team to implement and QA.   This will end up costing our client a great deal of money when the task is completed.

Is it worth it to remove the mobile URLs from their main website to be in adherence to John Mueller's advice?  We don't believe these extra mobile URLs are harming their search indexing.   However we can't find any sources to explain otherwise.

Any advice would be appreciated. Thx.

[ThomasHarvey]

I don't believe that having the mobile urls in the sitemap is causing any issue. Due to the fact that these urls presumably can be crawled anyway on the mobile subdomain. I can't see any negative for having these urls on a sitemap.

[RosemaryB]

Thanks Thomas.  The challenge we have is providing our client with a reputable source (not saying your not credible..lol) that states this is a negligible issue.

[ThomasHarvey]

This may help: https://developers.google.com/webmasters/mobile-sites/mobile-seo/separate-urls#annotations-for-desktop-and-mobile-urls

[ThompsonPaul]

As usual, Mueller's answers can be problematic because they're actually kind of vague. (e.g. his use of "if you use one of the other methods, make sure to follow those instructions separately" in that seroundtable article) Because the question asked in that article is specifically about responsive sites, non m. separate URL versions.

Here's the best I can give you... On that guidelines page you ,inked, Google specifically provides instructions for how to either include the mobile-URL versions of pages in the rel-alternate tag or by annotating the desktop sitemap to include rel-alternate info for the mobile URLS.

It does not make any mention of saying "or you can simply include the mobile URLs in the sitemap as well." Google's usually pretty good about telling us when there is more than one alternate method, while indicating which one they prefer. in this vase, I have to assume the conspicuous absence of any mention of including mobile URLs separately means it shouldn't be done.

Still conjecture, but does that make sense?

I'd definitely say it's imperative that the rel-alternate/rel-canonical treatment must be in place. Beyond that, I suspect it's a crawl budget/crawl efficiency issue, not an actual "indexing will break if mobile URLs are in sitemap" situation. As such, I wouldn't want to prioritise an expensive solution to this over whatever other more high-impact projects might be awaiting funding.

Just for the hell of it, I'll tweet at the Google guys to see if I can get a direct response to "will it cause harm" and let you know if I hear back.

I know this is just another perspective, not anything definitive, but hope it helps?

Paul

[RosemaryB]

Paul
That was an excellent response.  I also appreciate you going out of your way to hit up Google directly about this as well.

Yes we believe that this it is completely unnecessary to employ valuable resources to resolve a very minor issue.  However our client would is going to ask us to back our argument.

Thanks again

[RosemaryB]

Hey Paul

Did you get any response after tweeting Google? Thx.