How many Google AdWords promotional codes can be used?

I currently have a $100 coupon for google adwords.

Once that expires, can I just go to Billing > More Options > Apply Promo Code and add another one?

Thanks in advance.

Promotional codes are limited to one per account so it won’t be possible to redeem more than one promotion code for any Adwords account. If you have already applied a promotional credit to your account, you won’t be able to redeem another.

Therefore, these codes can only be redeemed up to 14 days after the creation of an AdWords account. If you created your AdWords account more than 14 days ago, you will not be able to redeem the code. Note that Google will not accept or replace expired vouchers.