As an example, here are the T&C of a nanny agency I've used - basically refund if the nanny doesn't start, and they'll find you up to 3 new candidates at no cost if she leaves within 8 weeks. So if the au pair agency has something similar then you may at least get someone else without paying another fee
Should the Candidate fail to take up an Engagement A FULL REFUND WILL BE MADE provided the Client advises the Agency, in writing, within 7 days of the failure. First and foremost the Agency will endeavour to find the client a replacement. Should this not be possible The Agency will provide a full refund.
4.3 The Agency cannot guarantee that the Candidate will complete his or her proposed length of Engagement.
4.4 If the Engagement is lawfully terminated by the Client or Candidate within 8 eight weeks of the date of commencement of a permanent Placement or within the invoiced period of a temporary Placement, the Agency will use all best endeavors to find a suitable replacement Candidate for the Client by reference to the Candidate’s experience and/or qualifications and the Client’s job specification from the date of the Client’s notification to the Agency at no extra cost to the Client. We offer a maximum of 3 replacement candidates.
A refund will only be valid provided that:
the Client notifies the Agency in writing within 3 days of the termination of Employment;
the Client allows the Agency to introduce a suitable replacement Candidate to the Client, The Agency is given 14 days to provide this
A replacement cannot be found;
all payments due to the Agency under these terms and conditions have been made by the due date;
the Client has not failed to carry out any of its obligations under these terms and conditions and current employment legislation;
the Candidate did not leave due to a change in the job description or a change in the work location, or due to unreasonable working conditions;
the Placement did not fail as a result of unreasonable demands by the Client;
the Client has requested that no replacement Candidate be sought
the Client has not found a new carer via another source after advising the Agency to look for a replacement Candidate;
the client has not varied the request for replacement from that of the original specification;
4.5 In the event that the Agency puts forward a Candidate (or Candidates) that it considers to be suitable by reference to the Candidate’s experience and/or qualifications and the Client’s job specification and the Client unreasonably fails to offer the Candidate a position on the same terms as the previous Candidate’s terms, then the Agency shall be under no further obligation to offer further replacements or a refund of the Introductory fee.
4.6 If the Client finds the Candidate unsuitable yet retains the Candidate in their employment the Client is liable to pay the full Agency fee and the Agency will offer no refund.
4.7 The Client will no longer be eligible for a refund after the first Candidate has been replaced.
4.8 Whilst the Agency shall endeavour to find a replacement Candidate the Agency makes no guarantee that such a Candidate will be found.
4.9 Once one replacement candidate has been found, there are no further refunds or replacements offered, In the event that a free replacement cannot be found by the Agency. The Agency will offer the client a refund for the original fee paid minus £75.00 Admin charges and less our standard rate of Temporary nannies of £30 a day for each day , the nanny has worked within the 8 week period. After 8 weeks the candidate is deemed satisfactory and no refund will be given.