Airtable Interface Limit crossed of 50. What should I do now?

You should be able to do this with 1 interface.  For each record in your of your projects table, you need to add an email address field that has the emails of the clients that are able to see that record.  In your interface add to your filter where your new email field matches current user email.  

Now you can show your clients only the projects that are theirs all through a single interface.

Hey Dan, Thanks for the solution.

We have 3 team members and 100+ clients. We can't add all clients as paid members. It would be expensive. Any other solution?

Read-only users are free in Airtable, so all 100 of those users would be free if you don’t give them commenting or editing access. 

As @Dan_Montoya outlined above, you only need to create one interface, and have it filtered to show the currently logged in user just their own records (i.e. records where you have attached them to the user field).

However, one important thing to note is that Airtable‘s interfaces were not specifically created for external clients, because there is no privacy. They can see the list of all your other clients from your interface. (When you are logged into the Airtable interface, click on the "Share" menu in the upper right corner of the screen, and then click on "Manage Access". Even if you are a read-only user, you will see a list of all the other people — with their email addresses — who also have access to that interface.)

Also, they all of are your users are required to signup for their own Airtable account, and as mentioned above, if you make them editable users, then you have to pay for them too.

If you want to explore official client portals that were designed for external clients, you may want to explore using a portal tool like JetAdmin or Noloco.

I gave an entire webinar on Noloco at this link entitled Building a Client Portal on Noloco Powered By Airtable. 

There are also other Airtable portals available too, but those 2 are my current favorites. 

p.s. If you have a budget for your project and you’d like to hire an expert Airtable consultant to help you with any of this, please feel free to contact me through my website: Airtable consultant — ScottWorld