# Merge fields — what personalises

> Names, numbers and dates per recipient; fixed fields per campaign; how a CSV column becomes a field.

Section: Designs & data · HTML: https://app.multiplied.studio/docs/designs/merge-fields · Index: https://app.multiplied.studio/llms.txt

_This page is a structure-only placeholder: the Studio UI it describes is being redesigned, so step text and screenshots land with the new UI._

## Two kinds of field

- **Campaign fields** — the same for everyone (headline, colour, offer). Set in the editor.
- **Personalised fields** — one value per recipient (first name, points, renewal date). Supplied by a CSV column.

## Mapping

On upload you map each personalised field to a column. Columns you do not map are ignored. A field you leave unmapped keeps the value saved in the design, for everyone.

## Value types

All CSV cells are text. Number fields (a count, a currency amount) are read from the text; a value that does not parse gets the field's fallback.