Data mapping

Data mapping is the assignment of one system's fields and values to another system's fields and values. It defines what is transferred where and how data is converted along the way, for example tax rates, payment methods or account numbers.

Explanation

Two systems almost never describe the same thing in the same way. The shop knows "first name" and "last name", accounting only "name". The shop stores the tax rate as a number, accounting expects a tax key. For each field, the data mapping records where the value comes from, where it goes and which rule applies in between.

A good mapping covers three levels: the field assignment (which field goes where), the value assignment (which value becomes which, for example "PayPal" to a specific clearing account) and the rules for special cases (what happens with empty fields, texts that are too long or unknown values). It should exist in writing and be approved by the subject-matter experts in the company, and for accounting data also by the tax firm.

Example from everyday integration work

Orders from a shop are supposed to go to DATEV as postings. The mapping defines: gross amount becomes turnover, order number becomes document field 1, order date becomes document date. Revenue at 19 percent goes to a different revenue account than revenue at 7 percent. Deliveries to other EU countries get their own accounts. Each payment method gets its own offsetting account. Only when this table is in place can the integration be programmed and tested cleanly.

How it differs from related terms

• Interface: the entire connection. The data mapping is its rule set.
• API: supplies the fields that get mapped. What it does not supply, no mapping can produce.
• Bidirectional integration: needs a mapping for each direction and additional rules for conflicts.
• DATEV posting batch (Buchungsstapel): a common target of a mapping, with fixed columns.

Relevance to our services

We create the data mapping together with you before programming. It is part of the fixed-price quote and helps determine the effort, see What does an integration cost? For accounting data we align it with your tax firm, for example in a DATEV integration.

Updated: 10/20/2026