Any accountants out there? Payroll RTI sumbissions?

Hi,

I have recieved a letter from HMRC this morning stating that I owe them monies for class 1 National Insurance and interest is added to this on daily basis. So not good stuff! I believe their calculated amount is incorrect as I work through my limited company and I didn't step over the personal allowance threshold for tax year 2014-2015.

One thing I must admit that I wasn't aware that RTI submissions had to be submitted to HMRC on a monthly basis regardless of whether you pay yourself a salary on a monthly basis or not. This is something I just found out. I changed my accountant and since then RTI submissions have not been submitted to HMRC for which I wasn't aware of it.

My question is how can I let HMRC know what salary I paid myself for the last tax year? Does anyone have a template letter which I could use to inform them of this situation?

Please reply soon.

Thanks.

Any help would be much appreciated.