Historically, post-WW2, mortgages rates have averaged around 7%
For various structural reasons, interest rates globally have been unusually low for years and look like staying that way
I remember my mortgage going up to 10% a couple of times, during economic squeezes and really shooting up to 15% for some months, to stop Sterling free-falling after the UK crashed out of the ERM.
There were many repossessions, with negative equity and resulting longterm debt
This time, although the pound would probably plummet again if markets become more sure of no-deal,
I expect (Mark Carney (Bank of England) to use all possible other levers, e.g. QE / printing money
- because an increase of more than about 4% could finish businesses already reeling from Brexit,
not just mortgage-holders.
So, check if you could be over-extended after Brexit and / or if your income could drop, e.g. from lower rents if you are an LL
Tenants might benefit - if they keep their job with full pay.
Not the time to buy property, unless it is to be your forever or very longterm home
Obviously avoid any new / increased loans without a long fixed rate;
especially avoid loans for consumer goods, including holidays - even a zero interest card could change abruptly, or you might need to keep the card as a reserve to cover a temporary shortfall.
Try to build up savings to tide you over possible increased expenses - groceries too - for maybe 6 months
Note: that's not 6 months income, it's 6 months extra expense