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OK this one's a little confusing, please try to follow along. We recently went through a rebranding where we brought a new domain online for one of our brands (we'll call this domain 'B' -- it's also not the site linked to in my profile, not to confuse things).  This brand accounted for 90% of the pages and 90% of the e-comm on the existing domain (we'll call the existing domain 'A') .  'A' was also redesigned and it's URL structure has changed.  We have 301s in place on A that redirect to B for those 90% of pages and we also have internal 301s on A for the remaining 10% of pages whose URL has changed as a result of the A redesign What I'm wondering is if I should tell Google through webmaster tools that 'A' is now 'B' through the 'Change of Address' form. If I do this, will the existing products that remain on A suffer?  I suppose I could just 301 the 10% of URLs on B back to A but I'm wondering if Google would see that as a loop since I just got done telling it that A is now B. I realize there probably isn't a perfect answer here but I'm looking for the "least worst" solution.  I also realize that it's not optimal that we moved 90% of the pages from A to B, but it's the situation we're in.