San Luis Potosí → Guanajuato · Autopista 57D México-San Luis Potosí
The night-time return from San Luis Potosí, San Luis Potosí, to Celaya, Guanajuato, deserves its own protocol: anti-glare driving glasses on, dashboard light dimmed to the lowest setting, and well-lit truck stops pre-identified as candidate rest stops. The 228 km (142 miles) of Autopista 57D México-San Luis Potosí and the 2h 32m of driving cross zones with patchy cellular coverage during the small hours. Approximate refuel cost on the way back stays at MXN 459.80 for the 19 liters (5.0 gallons) consumed. Forecast reimbursement for the night leg holds at MXN 1482.00 applying the prevailing MXN 6.50/km — without an automatic night premium in the tarifa promedio de mercado table. If the company pays night-driving overtime, open a separate line on the Clara receipt: the payroll integration already recognizes the entry. For the Canadian professional driving the 228 km between San Luis Potosí and Celaya, reimbursement of MXN 1482.00 stays excluded from T4 employment income provided the per-kilometre rate matches the CRA's reasonable allowance benchmark for the province. Canadian employers typically reimburse at the CRA reasonable per-kilometre rate (61¢ for the first 5,000 km in 2024) so the payment is excluded from T4 employment income. Keep the GST/HST-compliant fuel receipt from any NRCan-tracked retail network station used during the trip — Canada Revenue Agency (CRA) auditors regularly verify fuel-receipt GST/HST when reviewing T2200 declarations of conditions of employment. The San Luis Potosí→Celaya mileage must be logged with date, business purpose, opening and closing odometer readings inside the corporate expense system before month-end close to remain deductible.