How to best structure company accounts that we have multiple accounts we manage

How to best structure company accounts that we have multiple accounts we manage

Hi!

so our business we manage 3rd party accounts for our customers. Currently we track this in the account record by adding custom fields of all the information we need. This gets messy though if a company has multiple accounts we need to manage. Currently the solution is I make a new account record with same company name but with the type of account we manage in the name as well. For example:

xyz company (normal record)
xyz company - extra account name (multiple record)

my qurstion is that os there another way to structure this? Ideally where we can have just one account of the company but be able to include information for any other accounts we may manage  under that company.