Hi I’ve had my 19 plate fiesta st around 5 months and it has just done over 50,000 miles. 
 

since owning it the orange spanner symbol has come up but later goes away. Both online and the manual say it’s a service light. Today it has come back on but later went off again. 
 

I know for sure it’s had one service in 2022 as I have the invoice from the previous owner but I’m unsure when the next service is due and the light going off doesn’t help

Has anybody else experienced anything similar? 

It's not a service light.  It's a fault light, needs the codes read with Ford specific diags, ideally while the light is still on, as some codes clear on shutdown.

Do you have the ubiquitous Forscan and lead?

1 hour ago, Malio said:

Has anybody else experienced anything similar? 

See Ford Fiesta Owners Handbook.

https://www.fordservicecontent.com/Ford_Content/vdirsnet/OwnerManual/Home/Content?variantid=6894&languageCode=en&countryCode=USA&Uid=G1867936&ProcUid=G1867939&userMarket=GBR&div=f&vFilteringEnabled=False&buildtype=web

2 hours ago, TomsFocus said:

It's not a service light.  It's a fault light, needs the codes read with Ford specific diags, ideally while the light is still on, as some codes clear on shutdown.

Thanks for sharing this. The light has cleared but will definitely have it checked at out by ford.

10 hours ago, Malio said:

Thanks for sharing this. The light has cleared but will definitely have it checked at out by ford.

If you can use Forscan yourself, that's a better option for an intermittent fault like this.

If the light isn't on when you arrive at Ford, they might not find anything.  Some will refuse to read codes if the light isn't on.  Others will charge you regardless of any codes being present.

13 hours ago, Malio said:

 

I know for sure it’s had one service in 2022 as I have the invoice from the previous owner but I’m unsure when the next service is due

The ST requires servicing every 12 months or 12,500 miles whichever comes first.

Just now, Eric Bloodaxe said:

The ST requires servicing every 12 months or 12,500 miles whichever comes first.

Even if it's an ST-Line on 2 yearly servicing, it's still well overdue a service by now!

8 minutes ago, TomsFocus said:

Even if it's an ST-Line on 2 yearly servicing, it's still well overdue a service by now!

And it's hard to see how anyone could miss it. My car starts flashing the "change engine oil soon" message on the display at every start-up a couple of weeks before service is due, my previous 2018 ST-Line did likewise.