I was fed up of printing off SATs marking schemes and having about 85 pages to flick through each time I marked a paper, so I’ve put all the answers for each paper onto one page to make it much easier for you to mark. All full mark schemes can be found on https://www.gov.uk/education/primary-curriculum-key-stage-2-tests-and-assessments
A user named GammaRay has written something similar to this on his resources, and I’m going to use it for mine too: if you charge for your resources, then please don’t download mine. All my resources are provided on a share and share alike basis, not those seeking to derail a collaborative community.
The 2018 pack can be found here: https://www.tes.com/teaching-resource/ks2-2018-sats-one-page-answers-the-mark-scheme-condensed-onto-one-page-per-sats-paper-12050241
The 2017 pack can be found here: https://www.tes.com/teaching-resource/ks2-2017-sats-one-page-answers-the-mark-scheme-condensed-onto-one-page-per-sats-paper-12050998
The 2016 pack can be found here: https://www.tes.com/teaching-resource/ks2-2016-sats-one-page-answers-the-mark-scheme-condensed-onto-one-page-per-sats-paper-12053609
The 2016 sample pack can be found here: https://www.tes.com/teaching-resource/ks2-sample-2016-sats-one-page-answers-the-mark-scheme-condensed-onto-one-page-per-sats-paper-12054340