"Siemens has multiple Hilton codes (D323009803, 323009803, N0079268, 302844100) reflecting different business units and tiers. hotelcorporatecodes.com notes Siemens in the "Sometimes" category at Hilton. UK/Europe Hilton properties have increased enforcement since 2022 — Siemens has major Munich HQ operations where Hilton properties regularly encounter Siemens employees. FlyerTalk's London Hilton enforcement thread documented: "show a company ID card, or pay the full walk-up rate." German Marriott properties near Siemens facilities: medium-high risk."

"One thing I am curious about is whether the hotel CRM shows the booking channel. Most true corporate travel is booked through something like Concur, AMEX GBT, CWT, etc. If the agent sees the booking come through one of those channels with a person's name on it and then gets a card or photo ID (not corporate ID) from said person, it's a pretty low fraud risk. But if it is a reservation through the hotel's channels using just a typed-in code, then I'd think they would have reason to be more strict in seeking proof of affiliation."

"I have used heavily discounted corporate rates for many years all over London, and have not yet been asked for ID. If I was, all I could do would be to send an email from my work account which at least is clearly from the associated company."