Hi Varun

Thanks for reaching out to Lucid support. There isn't an automated way to merge two Lucidchart accounts into one however you can move all of your documents into one of the two accounts and then close the other. 

To transfer your documents share the document with the account you would like to transfer the files to. Once you share the document simply go into your account you would like to own the documents and make a copy. The copy will show up in your account under "My Documents" and the owner of the new copy will be the current account. If the original document is shared with anyone else you will need to reshare the copy.

Once your documents are all in one account you can close the other account by cancelling your subscription and then navigating to your Account Settings and select “Close Account” in the left navigation bar. Please note that closing your account will also close any Lucidspark account tied to the same email.

Hope this helps!