When banking experts Barclays wanted to make a statement supporting the end of the Defense of Marriage Act (DOMA) in the US, they did it in the most visible way they could think of – plastering a huge rainbow flag across their corporate offices on New York’s 7th Avenue.

Bold gestures aside, Barclays is keen to prove they really are serious about giving back to the LGBT community. And the work they are doing makes a great case study into the value of what firms call ‘corporate social responsibility’ and how it can be a pillar of a successful business.

Much of it is barely noticed by the public. Last night (11 July) saw Barclays support north-west England’s Lesbian and Gay Foundation (LGF) with their Annual Charity Summer Event in London. Guests got together to enjoy canapés, networking drinks and entertainment from Scottish comedienne Rhona Cameron. The cash raised will go to the Safer Schools campaign to try to free kids from homophobia and transphobia.

And it’s not their first association with LGF. In 2012 they supported the charity’s inaugural Homo Hero Awards, to celebrate LGBT people and their allies who make all the difference to the local community. This May, for IDAHO (International Day Against Homophobia and Transphobia), they worked with LGF to put 1,600 posters in their branches and publicize the event on 3,500 ATMs around the country.

Kathryn Townsend is one of the co-chairs for the UK/ European arm of Spectrum – Barclays’ LGBT employee network. She told us the IDAHO activity shows the firm takes its responsibility to citizenship seriously.

‘We wanted to show Barclays as a supporter for the LGBT community against homophobia and transphobia nationally through the poster and ATM campaign. That made me so proud to work for Barclays.’

Then last month (June) the firm covered the outside of their New York office, close to Time Square, with a giant digital rainbow flag to celebrate the Supreme Court’s decision to strike down the anti-gay Defense of Marriage Act.

Townsend says: ‘Normally that video wall shows our corporate logo, the blue eagle. I couldn’t believe we had done something so public.

‘In this time of governance and sign-off you get delays and can’t always do things like this. So for Barclays to do that, I was just so proud. I wish I had been able to fly out to see it.’

It was a big moment too for Simon Fillery, global head of diversity and inclusion for Barclays Corporate and Investment banking, who heads up their LGBT agenda.

He says: ‘For us it was huge. It was the first time the screens on the front of the building had been used for anything apart from business purposes. Basically the network there took a huge lead and wanted to make a real statement around DOMA.

‘We had huge senior support to keep the image up over the New York Pride weekend from the Friday all the way through to the Sunday, it just made sense. It got a great buzz around it on social media with people who have nothing to do with Barclays sharing the image.’

It wasn’t mere symbolism. Barclays was the first firm on Wall Street to equalize domestic partner benefits for staff.

And it has become one of the first firms operating in Asia to do the same – extending access to things like medical cover to same-sex partners of its employees in Australia, Singapore, Hong Kong, Indonesia, Malaysia and Thailand.

Fillery believes there are good business reasons for doing all this – aside of it being the right thing to do too.

He says: ‘From my personal experience there have been opportunities which have come up in New York which I’ve had to think about a different way because it would mean I’d have to leave my life partner behind.

‘Anything that hinders us in being able to move talent around the globe to where we really need them to be is something as an organization we would oppose.

‘It comes back to our core principles, making sure we have respect for our colleagues and our customers.’

Much of what firms do in their corporate social responsibility agendas is much smaller and more grassroots based, and Barclays is no exception.

Townsend says: ‘It is really happening because people are passionate about it and want to get involved. A lot of these things come from people getting in touch with the network and saying: “I’ve got an idea, can you help?”

‘Sometimes it may be small events, like a bake sale, others might be big events. We will try and provide resources whenever possible and some of that will be time and energy, not just financial commitment.’

Fillery remembers how he got involved with Albert Kennedy Trust [AKT], an organization helping LGBT homeless youths in the UK.

He says: ‘I helped set up the LGBT network a long time ago and was lucky enough to win an award internally and got £10,000 [$15,000 €12,000] to give to the charity of my choice.

‘That has led to me getting much more involved with the community because I now sit on the board of Albert Kennedy Trust.

‘It is one of the best things that has ever happened to me. It has really broadened my horizons and made me think about things in a different way.’

Again the work is reflected in the US, where Barclays supports the Ali Forney Center which works with homeless LGBT youths there – a huge problem which often fails to attract mainstream funding.

One of the lessons for companies who want to be taken seriously for their lesbian, gay, bisexual and transgender work is not to be tokenistic or frightened of doing something meaningful.

Another example is the firm’s sponsorship of Pink Dot, the annual pride celebration in Singapore – at first glance a safe bet, but not when you consider that homosexuality is still illegal in the island nation.

Fillery says it is important for them to support the campaign to get LGBT equality in Singapore:

‘As a forward-thinking organization if we are going to be able to attract the best and the brightest we need to be making sure we really are walking the walk in terms of equality and respect in the workplace.’

That attitude means the firm doesn’t just support the well-established London Gay and Lesbian Film Festival but also an LGBT cinema festival in India.

And there are plenty more examples.

Barclays has been one of the best fundraisers for the AIDS Walk New York, an event GSN is also a partner of, for four consecutive years, raising $170,000 (€133,000) in 2013.

The bank also supports Immigration Equality, helps God’s Love We Deliver get meals to the sick and those with HIV or AIDS in three states, and regularly has volunteers at New York’s Gay Men’s Health Crisis, among other places.

Colleagues have given CV workshops at the LGBT Harvey Milk High School and are regular supporters of the Gay, Lesbian, Straight Education Network gala dinner.

Back in the UK, the Barclays’ Spectrum Gala dinner last year raised over £60,000 ($89,000 €70,000) for Ben Cohen’s Stand Up Foundation which helps stop LGBT bullying.

And, on a smaller scale, bankers ran a Money Skills workshop for Topaz, an LGBT Youth Group in the Oxfordshire area of England.

As Townsend explains, Barclays dedicates some of its workers time to helping these activities.

She says: ‘Barclays are fantastic when it comes to giving you time. There is no problem putting forward a request to take a day or two to do some citizenship activity.’

Despite this, the bank is only now waking up to the need to publicize this good work.

Townsend tells the story of the firm’s legal team doing a Paris to Milan cycle ride raising over £250,000 ($370,000 €290,000) for UNICEF. But when she asked if they had issued a press release about their achievement, they confessed it hadn’t occurred to them.

‘People who are doing it are passionate about what they’re doing and they don’t even think of the PR point of view,’ she says. ‘But it is great to share those things more widely. It’s great if you will have people come and work for us or bank with us off the back of this because it’s entirely genuine.’

Fillery says ‘shining a light’ on this community work is becoming a greater priority.

And there is a good reason why.

‘One of the main pillars we have as an organization is around citizenship so supporting the communities in which we are doing business,’ he says. ‘Our LGBT colleagues are playing a full part on that, operating on a global basis and working with our community partners around the globe.’

Barclays is still developing in this area and finding ways to do more. But there is a clear message for other businesses here, big and small. Working with the community, including LGBT people, is good for your staff, good for your customers, good for society and good for business.

You can follow Barclays’ Spectrum on Twitter here.