The Society’s branch, on Mercer Row in the town, has £1,000 to split between three local good causes, chosen by colleagues and members.
But who gets the most money will be decided by the number of votes received.
The charities in line for a donation are: Lincolnshire Wolds RDA, the Multiple Sclerosis Society and the Thirteen Plus Project.
The Charity Choices campaign will launch on Monday, May 9, and run for two weeks. The number of votes received for each charity by Friday, May 20, will determine the amount of money each receives.
The one with the most will receive £500, second place will get £300 and £200 will go to the charity in third place.
The campaign is supported by Yorkshire Building Society Charitable Foundation, which N&P is part of.
Claire Corn, manager of N&P’s Louth branch, said: “We know how important our chosen three charities are to our local community so we’re delighted to be making a donation to help them continue their important work. Just how much they receive though will be up to our customers and members of the public.
“In this campaign you will decide which charity gets the most, so we hope as many people as possible will take a minute to pop in and make their vote count.”
A total of 160 branches and agencies around the UK will take part in the 2016 Charity Choices campaign in May, totalling £160,000.