I purchased NI products using different accounts. Is there any way I can change the account I purchased it from?
It is not good to use multiple accounts for so many products in any way.
Use one account instead.
Is there a fee for license migration?
Nope. Log into the account you want to move the licences FROM. View the "My products and serial numbers" page and at the top of the page there's a link for licence transfer. Follow the instructions there and you're good to go
-- Mike
You can contact NI's support team to request a merge of all your NI accounts into a single one. This will likely be a better option, as NI advises to not use several accounts to register your products.
Provide them with the following information: