Multiple entries database Update

Hello everyone,
I really need your help on this and it’s a very urgent matter, so I hope you can help me!
Let me give you the context.

I have 2 sorts of users in my database:
Brands that push special offers and clients.

For each brand, our solution creates a “CODE” . This code is unique to each brand . When a client is on the app, he needs to enter this Code (that he received by email) to have access to the specific offers of the brand. (If you don’t have the CODE, the promotions are not shown)

I can manage this.

The problem is that along the time, one client can receive several codes from different brands…and so, he will be invited to enter the CODE for each new brand. My question is:

For a same client, can I store several CODES in the database and how? (Remember, a code can be added along the time not all in once)….so I can display the special offers from each brand the client has a code.

Thank you very much for your help