To manage accountant access:

1. Go to Settings → "Toegang en boekhouder" (access and accountant)
2. In the Boekhouder (accountant) section, use "Add accountant" to add the contact details
3. Send the invite when you want them to create an account
4. Open Manage access to set page permissions

Accountant access is free on every plan; it does not require Pro or a team seat. Common statuses are contact-only, invited, active, and revoked.