This week I have been invited to an 80th birthday party, but before I get any of the cake, I will have to earn it.

The party is not for a person, but a thing, and that thing is generally known as the Citizens Advice Bureau - although that’s not its official name, as I will explain in a minute.

I happen to be a friend of the chair of the local branch - some of my best friends are chairs - and she contacted me at Christmas to ask: “Is there any chance you could do a bit of research and give a brief talk about the CAB in Swindon over the last 80 years?”

It’s for their AGM, which is on Thursday.

I realised just how little I knew about the CAB, including that they are celebrating their 80th birthday, but I will do almost anything for birthday cake, so I said yes.

I quickly discovered the national body is, in fact, now called just Citizens Advice (and the local branch is Swindon Citizens Advice). The Bureau was dropped no less than 17 years ago, although nobody seems to have noticed yet.

This is normal in Swindon - a town where old names die hard.

This paper’s, for instance. Look at the front page: it’s called the Swindon Advertiser, which was its original name, as long ago as 1854, and which it reverted to in 2007.

Yet I still encounter lots of people who want to call it by its former name of Evening Advertiser.

The confusion is even worse over at BBC Wiltshire, which is the radio station’s correct title, even though half the town still insist on calling it BBC Wiltshire Sound, which it stopped being in 2002.

A name with even greater persistence is that Norman Foster-designed, now Grade II-Listed iconic fancy warehouse at West Swindon that everybody I know calls the Renault Building (including me, I have to admit), even though it hasn’t been that since way back in 2001, when it became the Spectrum Building.

So I reckon the chances of anybody calling the Citizens Advice Bureau by its correct name, any time soon, are pretty remote, and it could be decades before anybody abbreviates it to CA instead of CAB, especially in Swindon.

I am going to tell this to local volunteers at their AGM on Thursday, when I do my little talk about the history, but I have some other news for them.

Although they are celebrating the CAB’s 80th birthday, by my reckoning their organisation is not actually that age. It’s older.

Although they rightly recall the date in 1939 when they were one of 200 bureaux to be formed in Britain on the day after we declared war on the Nazis, in Swindon it wasn’t so much a birth as a re-baptism.

After consulting the various resources in the local studies section of the Central Library, it seems to me that the people who were running the Swindon CAB when it began in 1939 had already been giving out advice in virtually the same manner since at least 1932, following the foundation of something called the Swindon Council of Social Services.

The only thing that really changed in 1939 was the name, and as we have already seen, that doesn’t necessarily mean much around here.

I have been trying to decide how to break it to them gently that they have got their sums wrong, but the cat is out of the bag, now I’ve written this.

I just hope they haven’t already bought the birthday balloons, but at least they have time to slip out and buy a few more candles.