San Luis Potosí → Guanajuato · Autopista 57D México-San Luis Potosí
Returning from San Luis Potosí, San Luis Potosí, back to Salamanca, Guanajuato, the itinerary retraces the same 222 km (138 miles) of the outbound segment, predominantly via Autopista 57D México-San Luis Potosí, adding another 2h 28m to the corporate odometer. Unlike the outbound leg, the homeward journey is usually executed at the close of the business day, when heavy truck traffic, accumulated fatigue, and dropping daylight all demand sharper focus. Anyone hoping to ease the arrival back into Salamanca, the sede de la refinería Ing. Antonio M. Amor de Pemex, may consider an overnight stop in a midpoint town and splitting the haul into two shorter stints. Fuel expense holds steady near MXN 447.70, totalling roughly 37.0 liters for the entire trip when added to the outbound segment. The return reimbursement reaches MXN 1443.00, doubling the aggregate payout for the full journey. Log each leg separately in the Clara receipt, with distinct timestamps, so the paperwork accurately mirrors the vehicle's actual movement. For the UK professional driving the 222 km (138 mi) between San Luis Potosí and Salamanca, reimbursement of MXN 1443.00 fits the subsistence allowance regime when paid at or below HMRC AMAP rates of 45p per mile for the first 10,000 business miles in the tax year. UK firms reimburse at HMRC AMAP rates (45p / 25p per mile) so the payment stays free of PAYE and NIC under approved mileage allowance payments rules. Retain a VAT receipt accepted by HMRC for input-tax recovery from the BEIS-tracked forecourt network forecourt used to refuel; His Majesty's Revenue and Customs (HMRC) compliance officers cross-reference fuel VAT receipts with the P11D return when reimbursement exceeds the approved rate. Excess paid above AMAP on the San Luis Potosí→Salamanca run must be reported via PAYE settlement agreement or it becomes a benefit-in-kind on the employee's tax code.