Selecting a Microsoft Office Primary Interop Assembly version

calendar_today Asked Jan 24, 2012
thumb_up 6 upvotes
history Updated April 14, 2026

Direct Answer

Using the earliest PIA version should work, albeit unofficially – see MS Office PIAs "backward compatibility". Using a later version may or may not work, and is not…. This is an advisory response with reference links, ranked #86th of 95 by community upvote score, from 2012.


The Problem (Q-score 5, ranked #86th of 95 in the VBA Core archive)

The scenario as originally posted in 2012

I’m writing a .Net application that utilises Excel. Any version of Excel from ’97 or later is acceptable, but I don’t know which version any particular client will have. Installing the Microsoft Office PIAs through a bootstrapper is no problem.

Which version of the PIA should I include in the installation package? Do I need every PIA version, or will one PIA version cover all required Excel versions?

Why community consensus is tight on this one

Across 95 VBA Core entries in the archive, the accepted answer here holds niche answer (below median) status — meaning voters are unusually aligned on the right fix.


The Verified Solution — niche answer (below median) (+6)

Advisory answer — community consensus with reference links

Note: the verified answer below is a reference / advisory response rather than a copy-ready snippet.

Using the earliest PIA version should work, albeit unofficially – see MS Office PIAs "backward compatibility". Using a later version may or may not work, and is not recommended.


When to Use It — vintage (14+ years old, pre-2013)

Ranked #86th in its category — specialized fit

This pattern sits in the 95% tail relative to the top answer. Reach for it when your scenario closely matches the question title; otherwise browse the VBA Core archive for a higher-consensus alternative.

What changed between 2012 and 2026

The answer is 14 years old. The VBA Core object model has been stable across Office 2013, 2016, 2019, 2021, 365, and 2024/2026 LTSC, so the pattern still compiles. Changes that might affect you: 64-bit API declarations (use PtrSafe), blocked macros in downloaded files (Mark-of-the-Web), and the shift toward Office Scripts for web-first workflows.

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Frequently Asked Questions

This is a below-median answer — when does it still fit?
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Answer score +6 vs the VBA Core archive median ~4; this entry is niche. The score plus 5 supporting upvotes on the question itself (+5) means the asker and 5 subsequent voters all validated the approach.

This answer links out — what are the reference links worth following?
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Read the first external link for the canonical reference, then search this archive for a top-10 entry in the same category — advisory answers are best paired with a ranked code snippet to close the loop.

This answer is 14 years old. Is it still relevant in 2026?
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Published 2012, which is 14 year(s) before today’s Office 2026 build. The VBA Core object model has had no breaking changes in that window. Three things to re-test: (1) blocked macros on downloaded files (Mark-of-the-Web), (2) 64-bit API declarations (PtrSafe, LongPtr), (3) any shift toward Office Scripts for web scenarios.

Which VBA Core pattern ranks just above this one at #85?
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The pattern one rank above is “Is there a compatibility issue between macros written for XLS, XLSX and XLSM?”. If your use case overlaps, compare both before committing.

Data source: Community-verified Q&A snapshot. Q-score 5, Answer-score 6, original post 2012, ranked #86th of 95 in the VBA Core archive. Last regenerated April 14, 2026.