Hi,
There is no limit to a cash gift.
We cannot comment on the tax implications of you receiving this gift while resident in another country. If you are resident in the UK, there are no UK Income Tax implications on the receipt of a cash gift, unless the cash gift generates interest or dividends. These would then potentially be subject to tax. Further guidance can be found here:
Tax on savings interest
Tax on dividends
As your parents are not UK resident, there are no Inheritance Tax implications on the gift.
Thank you.