Carrying cash from United Kingdom to United States
Two separate rules apply to any cash journey: one where you leave, one where you arrive.
Do you need to declare?
Yes: and on both legs of the journey. Leaving United Kingdom, HM Revenue & Customs requires a declaration above GBP 10,000. Entering United States, U.S. Customs and Border Protection requires a declaration above USD 10,000. The two rules are independent: satisfying one does not satisfy the other.
Travelling as a family or group?
The threshold applies to your combined total, not per person. A family of four each carrying a little under the limit is still over it, and splitting cash between travellers to stay under does not make it legal.
The two legs
| Leg | Limit | Form | Authority |
|---|---|---|---|
| Leaving United Kingdom | GBP 10,000 | Declare cash online (GOV.UK) or form C9011 | HM Revenue & Customs |
| Entering United States | USD 10,000 | FinCEN Form 105 (CMIR) | U.S. Customs and Border Protection |
The same threshold applies on the way out.
There is no limit on how much you may carry; amounts over USD 10,000 must be reported.
If you do not declare
United Kingdom: Cash may be seized and a penalty of up to GBP 5,000 applied.
United States: Seizure of the currency and possible civil and criminal penalties.
There is no limit on how much you may legally carry in either direction, the duty is to report it, not to keep under it. Failing to report is the offence.
Currencies
United Kingdom uses GBP; United States uses USD.
Sources: rules as of 22 September 2026. This is general information, not legal advice; always check the official authority before travelling.