How Much Interest Will I Lose ?

[CW1]

Hi,
Have lent someone £3000 from an ISA that pays 3.5%, which they're paying back at £100 every 4 weeks until they sell their house (not likely to be for a while !) when they'll pay the amount outstanding.
How much interest will I lose ?
Thanks

[Mass_Hysteria]

It depends what the balance of your ISA is. I think you will still get the 3.5% but on a reduced balance (£3000) you lose just over £100

[sandyRoe]

It will take 120 weeks to repay you. If the house isn't sold. You would have earned £105 interest in the first year, and a bit more in the second. Roughly, about £230

[dr b]

3000 x .035 = 105 per year. It will take 2.5 years to get paid back if the house is not sold, so roughly 262 pounds. On the one hand this ignores compounding of interest on the ISA but it also ignores the interest you will earn when you reinvest the 100 monthly, so that probably washes out.

[CW1]

Thanks guys.
It's an old ISA hence the decent rate so I won't be reinvesting the £100 in that. I'd been using the money in the ISA to overpay my mortgage but not going to even try work out how much I'd lose there LOL though I'll probably use the £100 for that. I've lent it to family so not gonna get penny pinching :)

[factor-fiction]

The answer also depends on what you do with the repaid £100 per lunar month- whether you can reinvest it in the ISA at 3.5% (unlikely), reinvest it elsewhere (probably at less than 2%) or keep it as cash