Is this an error coin please

[hobi12]

Sorry it's been a while I got this in my change the other day is it an error coin TY in advance

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[capnbirdseye]

What is it you see that makes you think it's an error ?

[FosseWay]

The denomination on the upper pic is more or less missing. I've no idea whether this is a weak strike (dirt in die) or whether it's post-mint damage. It isn't just normal wear though, otherwise the lions would be more worn.

[Figleaf]

In view of the rough surface on the right and the upper lion being significantly more worn than the lower lion, I think this was done outside the mint, presumably with a sharp acid.

Peter