Transferring child benefit NI to partner

Has anyone managed to transfer NI contributions from child benefit to their partner. I've applied to transfer the last 7 years but been told I can only transfer the last year as it is past the deadline and I must have a reasonable excuse to transfer more. All the advice I read makes it sound like you can transfer several past years of contributions?

Hi Poppopboogie88,

There are time limits for applying to have your child benefit credits transferred.
Your application should be made before the end of the tax year (5 April) following the relevant period for which you want to transfer the credits.
For example, if the transfer period is in the 2016 to 2017 tax year you should apply for a transfer before 5 April 2018.
If the time limit has passed you can still complete the application form, but you must give the reason why you did not apply on time.
If the circumstances are reasonable HMRC can still award the credits as long as you meet the transfer conditions.
This information can be found on the CA411A application form - Apply for National Insurance credits if you’re a parent or carer

Thank you.