Small businesses offering SEO and other services to clients in the US and UK often need to create Gmail/Google accounts for clients. The problem is that you can only create 20 accounts per phone number and we do not want to associate our IDs to a phone number that only we have access to. Because we deliver the work to the client so they need to have access to this verification number in order to make changes or receive and send emails from those accounts.
We had been using Pinger and K7.net but it is becoming difficult to use these services as most numbers they provide already have many accounts registered on these numbers.
We are looking for a web based service where we can pay to get US based numbers that actually work. We will be needing at least 20 US based numbers where we can receive either Voice mail or Text messages or both per month.
Sometimes the SEO is a subcontracted service in another country, so engaging directly with the ultimate customer is not an option.
Depending on the size of the customer's business, it might not be feasible to get an email account for the SEO agency. e.g. I work at a large company and can only use company-supplied devices to access email and it can't be forwarded (without a lot of red tape).
Skype offers phone numbers, which could be one option.