(United Kingdom) Multiple Stock ISAs?
It is a very good idea to spread your ISAs over more than one stock broker.    However now that a lot of stock brokers charge an admin fee it can get expensive if you use too many. There is no need to tell your last year’s ISA provider that you are using a different one, however you MUST ONLY pay into one ISA provider in each tax year.
"The four countries we examined—Canada, the United Kingdom, Germany, and France—have separated their air traffic control functions from their safety oversight and regulatory functions, the report said. ""While safety and regulatory functions remain government-controlled, each nation has commercialized its air traffic control function into an [Air Navigation Service Provider] using various organizational structures."" http://thehill.com/policy/transportation/253073-audit-finds-significant-differences-in-private-air-traffic-control" 1.8% interest isn't bad, but unless you're a higher rate taxpayer a Santander 123 account might be better for you than an ISA. See http://www.theguardian.com/money/2015/mar/23/cash-isas-pointless-savings-revolution An ISA is a much simpler thing than I suspect you think it is. It is a wrapper or envelope, and the point of it is that HMRC does not care what happens inside the envelope, or even about extractions of funds from the envelope; they only care about insertions of funds into the envelope. It is these insertions that are limited to £15k in a tax year; what happens to the funds once they're inside the envelope is your own business.  Some diagrams: Initial investment of £10k. This is an insertion into the envelope and so counts against your £15k/tax year limit.                 +---------ISA-------+ ----- £10k --------->              |                +-------------------+  So now you have this:                 +---------ISA-------+                |  £10k of cash     |                +-------------------+  Buy fund:                 +---------ISA-------+                |    £10k of ABC    |                +-------------------+  Fund appreciates. This happens inside the envelope; HMRC don't care:                 +---------ISA-------+                |    £12k of ABC    |                +-------------------+  Sell fund. This happens inside the envelope; HMRC don't care:                 +---------ISA-------+                |    £12k of cash   |                +-------------------+  Buy another fund. This happens inside the envelope; HMRC don't care:                 +---------ISA-----------------+                | £10k of JKL & £2k of cash   |                +-----------------------------+  Fund appreciates. This happens inside the envelope; HMRC don't care:                 +---------ISA-----------------+                | £11k of JKL & £2k of cash   |                +-----------------------------+  Sell fund. This happens inside the envelope; HMRC don't care:                 +---------ISA-------+                |    £13k of cash   |                +-------------------+  Withdraw funds. This is an extraction from the envelope; HMRC don't care.                 +---------ISA-------+ <---- £13k ---------               |                +-------------------+  No capital gains liability, you don't even have to put this on your tax return (if applicable) - your £10k became £13k inside an ISA envelope, so HMRC don't care. Note however that for the rest of that tax year, the most you can insert into an ISA would now be £5k:                 +---------ISA-------+ ----- £5k --------->               |                +-------------------+  even though the ISA is empty. This is because the limit is to the total inserted during the year. You could use a stock-only ISA and invest in Exchange Traded Funds (ETFs). ETFs are managed mutual funds that trade on open exchanges in the same manner as stocks. This changes the specific fund options you have open to you, but there are so many ETFs at this point that any sector you want to invest in is almost certainly represented. "The answer is partly and sometimes, but you cannot know when or how. Most clearly, you do not take somebody else's money if you buy shares in a start-up company. You are putting your money at risk in exchange for a share in the rewards. Later, if the company thrives, you can sell your shares for whatever somebody else will pay for your current share in the thriving company's earnings. Or, you lose your money, when the company fails. (Much of it has then ended up in the company's employees' pockets, much of the rest with the government as taxes that the company paid).  If the stockmarket did not exist, people would be far less willing to put their money into a new company, because selling shares would be far harder. This in turn would mean that fewer new things were tried out, and less progress would be made. Communists insist that central state planning would make better decisions than random people linked by a market. I suggest that the historical record proves otherwise. Historically, limited liability companies came first, then dividing them up into larger numbers of ""bearer"" shares, and finally creating markets where such shares were traded.  On the other hand if you trade in the short or medium term, you are betting that your opinion that XYZ shares are undervalued against other investors who think otherwise. But there again, you may be buying from a person who has some other reason for selling. Maybe he just needs some cash for a new car or his child's marriage, and will buy back into XYZ once he has earned some more money.  You can't tell who you are buying from, and the seller can only tell if his decision to sell was good with the benefit of a good few years of hindsight.  I bought shares hand over fist immediately after the Brexit vote. I was putting my money where my vote went, and I've now made a decent profit. I don't feel that I harmed the people who sold out in expectation of the UK economy cratering. They got the peace of mind of cash (which they might then reinvest in Euro stocks or gold or whatever). Time will tell whether my selling out of these purchases more recently was a good decision (short term, not my best, but a profit is a profit ...)  I never trade using borrowed money and I'm not sure whether city institutions should be allowed to do so (or more reasonably, to what extent this should be allowed). In a certain size and shortness of holding time, they cease to contribute to an orderly market and become a destabilizing force. This showed up in the financial crisis when certain banks were ""too big to fail"" and had to be bailed out at the taxpayer's expense. ""Heads we win, tails you lose"", rather than trading with us small guys as equals! Likewise it's hard to see any justification for high-frequency trading, where stocks are held for mere milliseconds, and the speed of light between the trader's and the market's computers is significant." The main difference is that the ISA account like a Cash ISA shelters you from TAX - you don't have to worry about Capital Gains TAX. The other account is normal taxable account. With only £500 to invest you will be paying a high % in charges so... To start out I would look at some of the Investment Trust savings schemes  where you can save  a small amount monthly very cost-effectively - save £50 a month for a year to see how you get on. Some Trusts to look at include Wittan, City Of London and Lowland From the FAQ I think it is fairly clear that it is OK: Can I open a Help to Buy: ISA with someone else? No. Help to Buy:   ISAs are only available to individuals. But, you can put more than one   government bonus towards the home you are buying. So, if you are   buying a home with someone else who is also a first time buyer, they   can open and save money into their own account and receive a   government bonus. Inference: if you are buying a home with someone else who is NOT also a first time buyer, they can't get their own account and get the bonus (but there's no problem with you doing so).  Alternatively - open the Help To Buy ISA, you'll still get the normal interest rate on it, and then argue the case with the conveyancer / solicitor once you actually buy the property and claim the Government bonus. In fact, here is the declaration you (well, specifically, your girlfriend) would have to sign at the point you jointly make the purchase. Nothing in there that forbids it being a joint purchase with a non-first-time-buyer either. It is allowed to transfer money between ISAs however you like in one year.  It does not count against the limit for how much you can pay into an ISA in a year, nor does it count as paying into two ISAs in the same year.  But make sure you transfer the money.  Don't withdraw it, then pay it into a new ISA. If your provider doesn't like you taking money out of one ISA while keeping another, then it's about time you found another provider.