You should configure your chart of accounts (SKR) and account length in DATEV UO.
Those settings can be configured in DATEV UO under 'Anwendungen > Stammdaten > Unternehmensangaben > Grunddaten Rechnungswesen'.
This allows you to choose account codes' length.
This information is then visible in Spendesk under Settings>Accounting.
👉 Account codes in Spendesk need to respect the formats configured in DATEV UO, otherwise export errors might occur. 👈
More information on these formats (still on our help center).