I received my letter from them within a few weeks. I also have a Small Earnings Exemption Certificate, but don't bother applying for one. I just received a letter from HMRC yesterday, stating SECs will NO LONGER BE VALID after April of this year! They are doing away with the certificate, and bringing in a new system. Apparently, when you do your self assessment for this tax year, they will then decide if you must pay Class 2 taxes, based on your profit. There wasn't much info in the letter they sent me, as it kept repeating the phrase that they would "send me further information as it becomes available". My certificate was supposed to be good up until April 2016, so I'm a bit ticked. Just when I begin to understand the system, they go and change it. lol