There's a better way to handle this than you might think, and it starts with flipping your mental model of how the data should flow. You're not alone in feeling stuck, this is a classic problem of wanting a single source of truth while juggling twelve separate pulls that each have their own quirks. The good news is that Excel already has the tools to make this work, and once you see the pattern, you'll wonder why you didn't try it sooner.
The core issue here is that you need a rule-based override system, not a manual one. Your January data is the baseline, it's clean, complete, and correct. February's pull, on the other hand, zeroes out January figures, which means you can't just stack the months and call it done. What you actually need is a way to tell your worksheet: "For January, always use the January pull. For February, use the February pull if it exists, but fall back to January if it doesn't. For March, use March's pull, and so on." That's not a spreadsheet problem; that's a logic problem. And the solution is a simple lookup structure that references the most recent month's data for each column, while locking earlier months to their original pulls.
Practically speaking, you're looking at a combination of `INDEX` and `MATCH` functions, or even a well-designed `IF` statement that checks the month and pulls from the corresponding tab. The key is to set up a mapping table that tells Excel which tab to reference for each month, then use that table to drive your formulas. For example, if you have tabs named `Jan`, `Feb`, `Mar`, and so on, you can write a formula that says, "Look at the month in this cell, find the matching tab, and pull the value from that tab's corresponding row." The override logic comes in when you decide that for January, you always reference `Jan`, regardless of whether `Feb` has newer data. You can hardcode that rule into the formula, so it doesn't matter how many times you refresh the data, January stays locked.
The real beauty of this approach is that it's built to be handed off. Once you set up the formulas and the mapping table, the person who loads the data doesn't need to understand the logic. They just paste the new monthly pull into the correct tab, and the consolidation sheet updates automatically. That's the kind of solution that feels like magic, but it's really just a matter of designing for repeatability. You're not asking Excel to think for you, you're giving it a clear set of instructions that account for the messy reality of your data pulls.
So here's the concrete takeaway: stop trying to make one formula do everything, and start building a small framework that separates the "what" from the "when." Map out which month each tab represents, decide which months should always reference their original pull, and then let a single formula pattern handle the rest. Test it with a few months of data, and once you're confident it works, pass it along with a note that says, "Just update the tabs." You'll save yourself hours of manual copying and pasting, and more importantly, you'll eliminate the risk of accidentally overwriting good data with a messy pull. That's the kind of clarity that turns a frustrating problem into a repeatable process.