The NHS Business Services Authority (NHSBSA) sends out certificates for the whole of the UK on behalf of the health departments in Wales, Scotland, England and Northern Ireland. They cannot issue you an exemption certificate until they receive the information from the HMRC saying whether you are eligible or not for Working Tax Credit (WTC) or Child Tax Credit (CTC).
To qualify for NHS tax credit exemption certificate your annual income for Working Tax Credit or Child Tax Credit purposes should be £15,276 or less and you should be a recipient of Child Tax Credit and Working Tax Credit, recipient of Working Tax Credit which includes a disability element or recipient of Child Tax Credit but are not eligible for Working Tax Credit. If you are eligible, you will automatically receive an NHS Tax Credit Exemption Certificate sent to you in the post.
To find out more information about NHS Tax Credit Exemption Certificates you can also call their Tax Credit Exemption Office on 0300 330 1347. Dial 18001 before this number if you are using a textphone (to use the Text Relay service). Or you may also ring the NHSBSA on 0845 609 9299. You can also learn more about the tax credit here.
Of interest, it's been reported that hundreds of people suffered "appalling" care at Mid Staffordshire, causing hundreds of needless deaths earlier this year and is now being investigated by police. According to Robert Francis QC, there's a need for a "reinstatement of professionalism" throughout the management of the NHS and its regulators.