Sharing a collection with an external organisation that uses bitwarden already

Hello! We’re currently considering to use BitWarden in our company.

We have 10 employees and an external team of 6 developers that work for an agency that’s already using BitWarden, so they all already have a paid bitwarden account.

Is it possible to add seats only for our own employees, and somehow share our passwords with the contractors without additional seats for each of them?