Spreadsheet or app for a coin collection?

For a few dozen coins, one person and a simple goal — “keep a list so I know what I have” — a spreadsheet is a sensible choice. One file, familiar columns, easy sorting and filtering, and with a little practice sums and pivot tables as well. There is no new program to learn and no data to migrate.

• The collection is small and grows slowly, and you are the only person adding to it.
• A simple list is all you need: country, denomination, year, grade, price — no photos and no long descriptions.
• You change the data rarely and do not need a history of changes.
• You already have a habit of making a backup of the file.

In that setup a spreadsheet can even be better than an app, because it does not ask you to give up the way you already work. The problems begin when your needs grow faster than the care with which the file is maintained.

A spreadsheet does not check what you type. The grade column can contain 2+, XF, “very nice” and an empty cell — all in one file, and all “valid” as far as the spreadsheet is concerned. You are the one who has to remember a single scale, a single date format and a single way of writing weight. With a few dozen rows that is doable; with a few hundred, mistakes creep in that are not obvious at first glance.

The second problem is photos. A spreadsheet can embed images, but with a larger collection the file grows quickly and becomes harder to move around. The more common approach — a separate folder of photos with file names matching coin numbers — works only as long as someone maintains those names by hand. After renumbering, moving the folder or adding a photo from a phone, the link breaks and a coin ends up without its picture.

The third problem is teamwork and versions. When a file travels by email, or sits in the cloud and several people edit it, you end up with “catalogue_final”, “catalogue_final_2” and “catalogue_corrected”. There is no single source of truth, and working out which version is current can take longer than the data entry itself.

The fourth problem is access control and history. Anyone who has the file can overwrite a purchase price or delete a row, and usually no trace is left. For a collection of real value this is not only a matter of tidiness but of data security and of settling a claim with an insurer.

• Different scales in one column: 2+, XF and “nice” side by side make filtering and comparison impossible.
• Numbers stored as text: “6.2 g”, “1,200 USD” and “about 30 mm” cannot be summed or sorted.
• Weight and diameter in one column, or purchase price mixed with current valuation.
• No inventory number, or duplicate numbers that leave no way to tell which coin a row refers to.
• Photos in a separate folder with no permanent link to the record.
• Price history overwritten without a date, so you cannot tell when a value came from and where.
• A backup on one computer only, or no backup at all.

None of these mistakes is the spreadsheet’s fault. They follow from the fact that a spreadsheet is a general-purpose tool: it has no concept of a coin, a grading scale or a catalogue, so it cannot enforce a correct entry.

This comparison does not say that an app is always better. It says what you pay for: a spreadsheet demands your work to keep it tidy, while an app takes over part of that work but adds its own constraints — a subscription, dependence on the provider and the need to migrate your data.

1. Fields and scales that fit numismatics: grade on a known scale, metal, mint, catalogue numbers, weight and diameter.
2. Photos linked to the coin, not kept in a separate folder.
3. Export of all your data in an open format, ideally a single file that can restore the catalogue.
4. Sign-in and permissions: two people can work together without emailing files.
5. Clear search and filtering by collection, grade, year and metal.
6. Fast data entry: a form that does not make you click through dozens of fields for every coin.
7. Transparent data storage: where the data physically lives and how it is protected.

The last point is often overlooked. If the app stops being developed a year from now, export is the only way not to lose your work. So before you enter the first coin, check that export exists and contains everything you need.

Do not start by entering the collection again from scratch. First tidy the spreadsheet: one column should mean one piece of information, and scales and units must be the same throughout the file. Only then move the data in batches — by collection, for example — and after each batch compare the number of records and a few randomly chosen coins.

1. Make a copy of the file and keep it as an archive before changing anything.
2. Standardise how grade, weight, diameter and dates are written.
3. Add unique inventory numbers if there are none.
4. Separate the purchase price from the current valuation and add the valuation date.
5. Move the data into the app and check that the number of coins matches.
6. Keep the old spreadsheet as a historical copy, but stop editing it.

A spreadsheet is not a bad tool — it is a bad tool for jobs it does not police. If your catalogue is to serve as proof of ownership, the basis of a valuation and a source of reports, choose a solution that enforces order instead of relying on memory. How to organise such a catalogue step by step is described in How to catalogue a coin collection.