**Reference for final published version:** Smith L E, Potts H W W, Amlot R, Fear N T, Michie S, Rubin G J. Adherence to the test, trace, and isolate system in the UK: results from 37 nationally representative surveys. BMJ 2021; 372 :n608. https://doi.org/10.1136/bmj.n608
**Link to pre-print:** https://www.medrxiv.org/content/10.1101/2020.09.15.20191957v1