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# How to Handle Legacy Data When Starting a New System
- URL: https://blog.jestor.com/handle-legacy-data-new-system/
- Published: 2026-09-17T22:34:12.000Z
- Updated: 2026-09-17T22:34:12.000Z
- Author: Bruno Bannach

Deciding how to **handle legacy data** is one of the first questions in any implementation, and one of the most commonly overthought. Bringing everything is rarely necessary and often harmful.

## Why importing everything backfires

Historical data carries the structure and the quality of the system it came from.

- Inconsistent records polluting a clean structure
- Fields that do not map onto the new model
- Duplicates imported and then reconciled manually
- Months spent on cleanup before anything runs

## What to bring, and what to leave

| Data                          | Decision                                             |
| ----------------------------- | ---------------------------------------------------- |
| **Active records**            | Bring — the process depends on them                  |
| **Core entities**             | Bring — clients, suppliers, products                 |
| **Closed historical records** | Usually leave, or archive separately                 |
| **Fields nobody uses**        | Leave — the new structure is the chance to drop them |

## How to do it in Jestor

1. Upload your existing spreadsheet to **Jestor** — apps and processes are generated on top of it.
2. Bring core entities first: clients, suppliers, products, cost centres.
3. Import active records, and leave closed historical ones in an archive.
4. Set field types deliberately during the import — currency, date, connected.
5. Set the label field on each related table before connecting records to it.

## Why choose Jestor for implementation?

Uploading a spreadsheet into **Jestor** generates the structure automatically, which removes the slowest part of an implementation: rebuilding a data model you already had.

Because data is exportable at any time, the decision about what to import is not permanent — historical records can stay accessible in their original form rather than being forced into a new structure.

## Frequently Asked Questions

### Should I import all history?

Usually not — active records and core entities are enough. See [jestor.com](https://jestor.com/?ref=blog.jestor.com).

### Can I start from my spreadsheet?

Yes, uploading it generates apps and processes on top of it.

### What should I fix during import?

Field types and connected labels, before volume grows.

## Video Tutorial: Step by Step

Check out other practical tutorials on the Jestor YouTube channel.

## Get to know Jestor

With **Jestor**, you can automate workflows, connect teams, and build internal systems your way — all without code and powered by **AI**. Discover Jestor at [jestor.com](https://jestor.com/?ref=blog.jestor.com) and see how to take your company's operations to a new level of efficiency and control.