Excel says there are links but I can't find them — phantom links explained
Excel isn't lying to you. The External Links warning is accurate — there really is a reference to another workbook somewhere in this file. It's just not in a cell formula, so searching with Ctrl+F never finds it. Drop your file in below and every reference gets listed, wherever it's parked.
Why searching your formulas finds nothing
Pressing Ctrl+F and searching “within: Formulas” only checks what's typed into a cell. It has no visibility into four other places Excel stores references: defined names, chart data sources, conditional formatting rules, and data validation lists. Any of these can hold a live pointer to another workbook — [Budget.xlsx]Sheet1!$A$1, for example — without a single cell in your visible grid referencing anything external. Excel's link warning checks all of these, which is why it fires even when your formula search comes up clean.
The usual way this gets into a file
The most common cause is copying a sheet from one workbook into another. Excel doesn't just copy the cells — it copies every named range that sheet used, even ones you never see in a formula. If that source workbook had a name like TaxRate defined as =[Corp2024.xlsx]Rates!$B$2, your new workbook now owns a copy of that name pointing at a file it has never displayed. The same thing happens with pasted charts: the chart keeps its original data-source reference even after you paste it somewhere new.
How to actually find it
Check four places in order: open Formulas → Name Manager and scan every “Refers to” value for a bracketed filename; click each chart and look at the formula bar (or Chart Design → Select Data) for an external path in the series formula; open Home → Conditional Formatting → Manage Rules and read each rule's formula; and check Data → Data Validation on any dropdown cells for a Source field pointing outside the workbook. Upload the file below and the tool checks all four automatically and lists exactly where each reference lives, so you're not clicking through menus one sheet at a time.