Another option worth looking at for short term can be premium bonds, this calculates what your returns are likely to be and can do different cases on tax rate etc.
That calculator is way off, based on what me and four others have experienced (possibly a too small/unlucky sample). In the last two years I've won roughly one quarter of what they suggest.
Another option worth looking at for short term can be premium bonds, this calculates what your returns are likely to be and can do different cases on tax rate etc.
https://www.moneysavingexpert.com/savings/premium-bonds-calculator/