Unfortunately yes, you owe those taxes. Delaware franchise tax accrues every year that the entity exists on the state’s records, regardless of whether the company is active. Simply stopping operations does not dissolve the corporation. You need to formally file a Certificate of Dissolution with the Delaware Secretary of State.
Here is the bad news: to dissolve in good standing, you need to pay all outstanding franchise taxes, penalties, and interest first. If you owe for 2023, 2024, and 2025, that could be $1,200 or more in base taxes plus whatever penalties have accrued. Delaware charges 1.5% per month in interest on late franchise tax.
The process itself involves: (1) board resolution authorizing dissolution, (2) shareholder approval if required by your bylaws, (3) filing the Certificate of Dissolution with the Delaware Division of Corporations, and (4) paying all outstanding taxes and fees. The filing fee for dissolution is $204.
If you want a detailed walkthrough, there is a good guide at /2023/12/14/how-to-dissolve-your-delaware-corporation-or-llc/ that covers the step-by-step process including handling outstanding tax obligations.