What is the best Technical Support helpline for Yahoo services?

There is none. You use the help pages to resolve issues.

Caveat emptor

The toll free numbers you often see in answers claiming to be official staff that can solve your Yahoo problems are not staff. These are spam bots, and it you call they will tell you your computer has a problem they can fix if you give them your credit card number.

Please remember that Yahoo never charges for help.

Yahoo Customer Care on Twitter - https://twitter.com/YahooCare

Yahoo Customer Care on Facebook - https://www.facebook.com/YahooCustomerCare

Support is always free of charge from Yahoo! - https://help.yahoo.com/kb/mail/SLN6349.html?impres...

Yahoo Customer Care offers multiple support options including phone and email. In order to determine what support options are available for your issue you must go through the online product support site shown below.

Start here - https://io.help.yahoo.com/contact/index?page=home&...

Select the product you need support for.

Select the Topic that most closely matches your issue then select the Sub-topic.

Under Recommended options you will see the support options available for your issue.

If support by phone is available you will see a "Call Us" link. Click on this link to display a pop-up showing the Customer Care number, the hours of operation, and your estimated hold time.

If support by email is available you will see a "Email" link. Clicking on this link reveals a fill-in form. Fill out the form concisely and completely so this issue can be addressed properly.

There is none at present.