Wonga has said that each individual who received a letter claiming to be from a fictitious law firm will be given £50 compensation "for the upset this might have caused them".
The firm said that it had worked with a regulator and a "third party expert" to come up with the compensation figure.
Any Wonga customers who received a letter from from fake law firms Barker & Lowe or Chainey, D'Amato and Shannon between 2008 and 2010 have been advised to claim their compensation through the firm's website or by calling the freephone number 0800 840 0836.
The country's biggest payday lender apologised after admitting it sent 45,000 customers letters from fake law firms.
The payday lender's misleading practices has shown how unfairly customers have been treated in the past.