Self Assessment
https://www.gov.uk/topic/personal-tax/self-assessment
Employer PAYE
https://www.gov.uk/topic/business-tax/paye
Tax Credits
https://www.gov.uk/topic/benefits-credits/tax-credits
Personal National Insurance
https://www.gov.uk/topic/personal-tax/national-insurance
Personal Income Tax
https://www.gov.uk/topic/personal-tax/income-tax
VAT
https://www.gov.uk/topic/business-tax/vat
Child Benefit
https://www.gov.uk/topic/benefits-credits/child-benefit
HMRC Services & Information https://www.gov.uk/government/organisations/hm-revenue-customs/services-information