First Great Western say the problems started at 4pm. South West Trains were also hit but say the issue is now resolved. Staff are being asked to allow passengers onto trains where guards can be paid cash or by card. The mobile credit card machines used by trains have not been affected.
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Friday night's forecast for the west of the region
Ferry strikes, fuel shortages and iffy weather- it must be a Bank Holiday. Here's our guide to the weekend ahead
Friday night's forecast for the east of the region