› FINANCE, COMMERCE to ask someone to pay more than the real price or value of a product or service: The company denied it was using its dominant position in the market to overcharge customers.overcharge sb (by) $10/10% etc. The shop overcharged me by €5. Banks are able to overcharge because they have complicated tariffs that are difficult to understand.overcharge for sth Some landlords habitually overcharge for insurance, building repairs, and services. → Compare undercharge verb