Restrict a user from creating more than 'n' customers in Django admin

In Django admin, how can I restrict a user from creating more than 'n' customers开发者_C百科?

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if customer is added to the main model as an InlineModel, then you just need to specufy max_num property (docs).

If this is a main model (not inline), the simplest is IMHO to override ModelAdmin's save method and check if adding additional customer is allowed.