Basic principles: conditions of liability: liability for NICs - client in a country with a Reciprocal Agreement with the United Kingdom
Where the worker provides his services to a client abroad, the intermediaries legislation may not apply for NICs purposes (see ESM8110). However, where the duties are to be performed abroad with an overseas client there are exceptions to this general rule, depending on where the client is based.
Under a Reciprocal Agreement (RA) with a country outside the European Economic Area, a worker will pay social security contributions in the country where she is working. The United Kingdom has entered into 19 such agreements.
A contract involving a worker living in the United Kingdom and a client in the USA under which she works in that country means she would be liable to pay US social security contributions. She would not be an employed earner under United Kingdom national insurance legislation. The intermediaries legislation will not apply for NICs purposes.
Within each RA a provision allows for a posted worker to remain insured in the United Kingdom for national insurance purposes. Each RA sets out the time limit. For example, the time limit for the USA is 5 years.
The intermediary can obtain a certificate of continuing liability from NICO International Services. The worker on posting by the intermediary to the USA would be regarded as an employed earner under United Kingdom national insurance legislation by reason of the contractual arrangement between the intermediary, the worker and the client. However, the intermediaries legislation will not apply because in deciding whether the legislation applies you consider what the situation would have been if the intermediary had not been involved.