Apostrophe of noun ending in s

[baferrari]

The name of my company is Fatfaces. Because is the singular form of the name I would make a possessive by adding 's at the end which sound very odd a. It would be - Fatfaces's customers. Is this right or should I just add the apostrophe without the s to fit the last noun of the company name which is in plural(faces)?

[Mister Micawber]

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The possessive of singular nouns ending in -s are now standardized to the usual 's, with the sometime exception of classical and biblical names (Socrates', Jesus')-- though you will still find some varying opinions among style manuals.

This form of the possessive, however, is normally limited to nouns representing sentient beings-- a company would more often use the noun as an adjective: Toyota customers, Fatfaces customers.
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In your case, howevver