A single payment plan is any single payment that you set up to pay:
Corporation Tax
Miscellaneous (Payment References beginning with X)
National Insurance Contributions Class 2 (Deficiency Notice)
National Insurance Contributions Class 2 (Quarterly Bill)
Pay As You Earn
Self Assessment
Stamp Duty Land Tax
Tax Credits
Value Added Tax
If you have a different tax or duty to pay please look at the payment options on the reverse of your Notice to Pay or visit the HM Revenue and Customs How to pay instructions page.