The best site to get official receipts depends on the type you need. For education and government payroll in Mexico, Mi Portal FONE is the best option: https://fonemiportal.com.mx. It allows teachers and public employees to download pay stubs, view payment history, and check deposit dates. For tax-related receipts or CFDI, visit the official SAT website at https://www.sat.gob.mx. For utility receipts like electricity, water, or phone bills, use the official websites of each provider such as CFE or Telmex. Always ensure you're using a reliable and secure portal to access your documents.