Vlookup and duplicates

I have 2 spreadsheets, both with customer demographic information in them. The first is a "master" list that contains all customers and their corresponding information (Spreadsheet A) *each customer was assigned a unique id when created*. The second is a daily report that is run containing updated information for some of the customers (Spreadsheet B) this report is run daily and added to itself, or the previous day's report, so spreadsheet B is actually a compilation of daily reports that are run. Since spreadsheet B is compounding, it will have duplicate entries of customers and thier unique ID.
After I add the report data to spreadsheet B, I use vlookup to search spreadsheet A for any customers that appear on spreadsheet B. Vlookup will then populate spreadsheet A with the information for that corresponding customer. The issue is, since the report is compounding and added to daily, the customers show up multiple times. I would like for vlookup to reference the most recent addition of any duplicate found if possible rather than the first instance it comes across in the column.

Hopefully that makes some sense, its confusing for me reading it back.

The VLOOKUP formula I am using is: =IFERROR(VLOOKUP(B47,Source!$A:$M,6,FALSE),"Not Found")

The sample attachment shows the general layout

Arejay,

Based on your description I created a sample doc of what you are looking for.

Sheet A is a dynamic table based on the compiled data of "Sample Duplicate Data"

I did 2 helper columns to get a true "max if" formula
Sample Duplicate Data Column L
combined J and K to get date AND time.

Column M is your new "unique lookup" It is dynamic and will always take the most recent data as dates and times increase
Cell M2 copied down

Formula:

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Remove "AMY" from the bottom of the list, Sheet A will indicate the new "most recent" data.
Sheet A is a Index and Match lookup based on the Unique ID.
In Cell B2 Copy down and across.

Formula:

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NOTE: you will have to reformate dates and times to read as dates and times but you now have a dynamic table to look up the most recent entry per Unique ID.