I have taken out a UK student loan several years back whilst studying, it was interest free at the time, but now a low interest of 1.5% APR has kicked in.

I have scraped together enough to pay this loan off, seeing as they sent me a statement a few days ago stating that the first 12 month period has just ended and the 1.5% rate has just been applied. I now have 12 months before I'm hit with another 1.5% on this loan.

However I have just started a cash ISA account with my partner, which pays 1.8%.

The way I see it, the 1.8% tax free earning is greater than the 1.5% I will accumulate in interest fees on the load.

Is this a good idea. Should I invest the money and earn 1.8% profit? Or should I pay off the loan and avoid hitting another 1.5% charge?