University College London Hospitals NHS Foundation Trust complained in June 2015 that commissioners outside England use a "burdensome" prior approval process, where a funding agreement is needed before each stage of treatment. At the end of 2014–15 the trust was owed more than £2.3m for treating patients from outside England. A survey by the "Health Service Journal" suggested there was £21m of outstanding debt relating to patients from the devolved nations treated in the last three years, against total invoicing of £315m by English NHS trusts.