My mum is currently here in the UK to visit me on a Malaysian passport, hence she is not required to apply for a tourist visa and is granted 6 months stay from the date of arrival. She arrived in mid March and her ticket back to Malaysia is in early September (length of stay does not exceed 6 months). However, I would like her to extend her stay until early November as I have just given birth and would welcome the additional help/company. If we were to leave the UK in August for a holiday (perhaps go somewhere in Europe for a few days) before her 6 months is up and she reenters the UK again, will she be granted another 6 months stay from the date of arrival into the UK (though she will only plan to stay until early November) or are you technically only allowed to stay 6 months out of 12 months? Any advice will be much appreciated!
This is a bad idea.
While there is no official rule of X months in a calendar year, she will not just get another six months on return, at best will get let back in to take her flight back in September, and has a very high risk of being refused entry entirely.
Guidance for home office staff says directly (page 11):
There is no specified maximum period which an individual can spend in the UK in any period such as ‘6 months in 12 months’.
However, when deciding if someone is a 'genuine visitor' as opposed to somebody trying to use visitor status to reside in the UK, they will consider things like (page 10):
the number of visits made over the past 12 months, including the length of stay on each occasion, the time elapsed since the last visit, and if this amounts to the individual spending more time in the UK than in their home country
the purpose of return trips to the visitor’s home country and if this is used only to seek re-entry to the UK