US/UK tax treaty

[RP2525]

I am a non resident alien and I received refunds of 2 pensions from work in the US. I filled in a W8-BEN when requesting my refunds to ensure I was not taxed. Please can you inform me which tax treat this falls under for the US/UK? I need to input this when filing my taxes so I am not taxed on the refunds.
One company issues me with a 1042-S which appears to be correct for non residents and the other company a 1099-R which they are insisting is correct, but in order to not be taxed under the UKUS tax treaty should it not be a 1042-S I received? Either way I need to have the tax treaty number to input. Please advise. 

[DaveF1006]

Non-resident returns and questions are handled through our affiliate at Sprint Tax. Please contact them here for further information.