When supplying material to us in SD we require very specific files to be sent to us, the most useful way to fix this is following the below instructions:
The setting in the edit time line should be frame size 720 x 576, standard definition and please check in the export settings to make sure that the options 16:9 and Widescreen have not been selected.
When exporting the file select 720x576 - this may make your Television Commercial (TVC) look vertically stretched though it will then convert to the right aspect when it comes through to us.
If the TVC is an Apple ProRes file - it is possible that it has been saved as 16:9 during export, this means the file has reverted to 1024x576, whereas we need it supplied as 720x576.
To fix the issue, you need to export out as the default option and not choose the 16:9 option in the export settings.