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Notification/March 12, 2026/7 min

Checklist: preparing a retail merger-control file with calculations you can actually reuse

A well-prepared merger file is not only about correct results, but also about reproducible ones. This checklist helps structure a cleaner retail package before filing or pre-notification exchanges.

Author

Pyner Team

Published

March 12, 2026

Updated

March 14, 2026

Key takeaways

  • A strong merger file starts with auditable, stabilised input data.
  • Core assumptions should be standardised before maps, tables and exports are produced.
  • Reusable deliverables save time across every filing iteration.

Short answer

A reusable retail merger-control file should rely on auditable data, stabilised assumptions, readable maps and consistent exports. The goal is to rerun the analysis quickly whenever assumptions evolve.

Key concepts

Safe harbor↗

Start from auditable data

The first weakness in a file is often not the analysis itself but the quality of the inputs. If roles, addresses, banners and surfaces are not stabilised, the full chain remains fragile.

Before producing anything, the underlying dataset should therefore be auditable, or at least easy to review and reconcile. That reduces late-stage corrections and version gaps.

Standardise the core assumptions

Once the dataset is ready, the next step is to standardise assumptions: market-share metric, isochrone timing, banner grouping logic and treatment of edge cases.

The main gain is not only methodological. It is also organisational, because it becomes much easier to rerun calculations when an assumption changes.

  • choose one market-share metric per file
  • apply a coherent geographic logic across zones
  • document exceptions instead of hiding them

Prepare reusable deliverables

A good result should be exportable as a map, a table and a concise report. That trio dramatically reduces the time lost recreating the same analysis in multiple formats.

Reusable deliverables help both internal coordination and external-facing workstreams such as client notes or filing drafts.

Keep a clear trail of versions and judgement calls

In sensitive files, calculations frequently evolve. The real issue is not to avoid change, but to explain what changed, when and why.

A workflow with sharing, exports and lightweight version traceability is much more robust than scattered spreadsheets handled by multiple stakeholders.

Useful resources

Export documentation↗Safe harbor guide↗Contact us↗

Frequently asked questions

What makes a retail merger-control file reusable?

A reusable file keeps calculations, assumptions, maps and exports in a format that can be rerun quickly without rebuilding everything from disconnected files.

Why standardise assumptions before filing?

Because it reduces inconsistencies across zones, speeds up iterations and makes judgement calls easier to explain to stakeholders.

Which deliverables should be prioritised first?

A map, a calculation table and a concise report already cover a large share of internal and external merger-file needs.

Checklist

Build reusable files, not just one-off screenshots

Pyner centralises data, calculations, maps and exports so teams can iterate with less manual friction before filing.

Explore Pyner

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