System and method for automated transaction splitting

A system and method are provided for automated transaction splitting. A central repository gathers details of multi-category transactions between a first payee (e.g., merchant, investment firm) and one or more users. Each category's proportionate share of the total of the transactions is calculated and used to configure an average or model transaction. When a new transaction is received, it is automatically split among the categories based on the model transaction. Multiple types or tiers of model transactions may be applied. For example, a user-specific model transaction may reflect one specific user's history of transactions with the payee. A community model transaction may reflect multiple users' transactions. Similarly, one type of model transaction may reflect transactions with a single payee, while another type may reflect transactions with related payees (e.g., payees having similar businesses).