Political parties and candidates rely on donations from individuals—the Protecting Elections and Defending Democracy Act, 2021 strictly regulates third-party contributions and advertising, which includes unions and corporations.
Provincial political donations over $25 are eligible for tax benefits and donations of up to $427/year will receive 75% of that back at tax time. Tax receipts are issued by political parties for any donation over $25 and are emailed/mailed out around February of the following year.
For more information, please check the Elections Ontario website.