Claiming basic 20% Tax Relief on Personal Pension

Hi, I contributed a regular monthly amount to a personal pension during the last tax year, to which my pension provided added the 20% tax relief. However, towards the end of the year I made a larger lump sum contribution to my pension, the pension provider did not add the 20% tax relief to this amount. How do I claim this back within the tax return? (I also am due some higher rate tax relief my tax return however, this is more easily understood within the tax return), Thanks

It may simply be that they are waiting for the rebate from HMRC before adding it to your pension, you need to allow 6 weeks for it to appear. If it's been longer than 6 weeks then you should get in touch with your provider. Some providers (such as Standard Life) will "front load" the tax relief and add it at the same time as your net payment, others (such as ii) don't.