Signs that a spreadsheet has turned into a risk
Information is entered by hand in several places
When the same order, customer or figure has to be entered first from an email into a spreadsheet and then into some other system, every manual transfer is a chance for an error. The more copying steps there are, the more likely it is that the information ends up differing from the original somewhere along the way.
No one is sure which version is correct
When a spreadsheet is edited by more than one person, or saved in more than one place, it's easy to end up in a situation where no one is sure which version is up to date. This is especially risky when the spreadsheet directly affects something visible to the customer, such as a delivery or an invoice.
The same work step repeats every day the same way
If filling in the spreadsheet has become a routine that someone does the same way every day, that's usually a sign the work step could be done automatically, without anyone doing it by hand each time.
One person carries all the tacit knowledge of the spreadsheet's structure
When only one person really knows how the spreadsheet works, which tab needs editing at which stage and which formula must not be broken, the business is dependent on that one person. If they're away, the work stops or the risk of errors grows.
The spreadsheet no longer shows the full picture
When information sits in several separate spreadsheets or files, getting the full picture requires manual combining. That means decisions are often made based on outdated or partial information.
What's worth doing before switching tools
Don't jump straight into a new system based on a feeling alone. First describe what's slow, error-prone or risky about the current way of working, and for whom. This helps scope which part of the work really needs to be solved first, and which part can stay in the spreadsheet for a while longer.