Does anyone know about donor-advised funds for UK taxpayers? The only ones I've been able to find seem to charge large management fees, or have a prohibitively large minimum investment.
I spent an hour or so looking into this recently, and couldn't find any DAFs that were suitable for small donors. It's possible I missed one, though.
CAF offers a 'giving account', which is effectively a low-interest savings account. You can get immediate tax relief for deposits, but forgo returns, and can only donate to UK registered charities, so seems like a weak option: https://www.cafonline.org/docs/default-source/personal-giving/2573h_charityacc_web-app_pdf_220519.pdf
FWIW my tentative conclusion was that the best option for savings small-ish sums for giving later is a straightforward ISA. You don't get any immediate tax relief from paying into the ISA (you'll get this when you donate the money to charity) but you do get (tax-free) growth, and retain flexibility in when and how the money is donated. Returns are important if you think you might wait a long time before giving, flexibility seems important if one's motivation for giving later is the possibility of some high-leverage opportunities in the future. The main downside is that you can't easily bind yourself into future donations this way, but I thought this was outweighed by the other factors in my own case.
I looked into this a while ago and ended up with a similar conclusion. The main options (to my knowledge) are NPT-UK, Prism the Gift Fund, and CAF's giving account.
Their fees all seemed too high for me to actually open a DAF (although sometimes it's not transparent and you're just supposed to get in touch). In particular, yearly fees eat up a significant fraction of the money if you leave it in for decades, so it seems unsuitable for such plan. It's probably so expensive because there are relatively few people who are interested in such accounts, and there is a lot of administrative work done by the fund (Gift Aid etc.).