When via an import you have multiple same companies in your database, there is the option to select a primary company and then merge with a secondary company. However, when selecting the secondary company you can only choose one. If you have multiple same companies you have to repeat this process over again. We’d rather see that when selecting a secondary company for the merge the option is to select multiple companies and that Hubspot already suggests which companies to merge as being secondary companies based on the name of the selected primary company - selecting these multiple companies with a single click. Would save a lot of time in data cleansing.
Status: Idea Submitted
Yes unfortunately you do have to do them one by one. According to this help doc HubSpot will automatically deduplicate company imports when they have a matching "Company Domain Name" field, so ensuring that those are in the import and consistent could be one way to make sure this happens. If these are not included in the dataset, you may be able to extract them from an email if that is included.
Alternatively, you could try Insycle, which allows you to flexibly match and merge company imports in bulk without merging them one-by-one. You can match duplicate companies together using any field in HubSpot. Additionally, you can use either “exact match” or “similar” matching options, which will help you to identify more duplicate companies in HubSpot that otherwise would remain.
Full disclosure — I work for Insycle, but seems like it could save you time for this process.
Agreed! Please let us use the CheckBoxes to simply merge companies.
Upvoting based on multiple customer requests 
Simplifying this process is a must IMO.
Por favor necesitamos esta simplificación de combinar varios contactos y empresas de manera masiva.
This is needed asap!
Agreed. Please add the ability to merge directly from the companies list screen by selecting checkboxes. Going into each one by one is next to impossible with over 10,000 records.
Yes, please do this!
please do this!
Following
I know this post was from 2020 … and we still need this option in 2024! Please hubsot. 
Please make this available! Even as a toggle option for imports would be really helpful.
please make this work
Has there been no movement on this since 2020? It’s almost February 2025, can we please make this feature available!
Can we please make this simple yet useful feature available?
Still need this feature!
Please add a way to merge based on check marks – a simple feature like this missing feels predatory (probably can do this easily if you upgrade to a higher tier)
2026 and still begging for this feature!