An extensive refurbishment is underway in Lloyds TSB Bank in Maidenhead.
The building in the High Street is expected to re-open on Tuesday.
It closed on Saturday last week.
A spokeswoman said posters and flyers had been used inside the branch to inform people about the work and customers were being told about the plans by staff when they were served.
But some were completely unaware of the closure, which has seen them directed to other Lloyds branches in Slough Trading Estate and Bourne End to do their banking.
The spokeswoman added: "Our branches are at the heart of how we serve our customers and we are delighted to be improving our Maidenhead branch."
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