Letting Agent signs up a 17 year old tenant – EEK!

The problem you have is that minors are legally incapable of owning an estate and in the event that a minor signs a tenancy agreement under the trusts of land and appointment of trustees act which i believe was 1996 the landlord in effect becomes the trustee which makes it very difficult to serve notice and end the tenancy.

You do have a comeback on the letting agent as this is negligence on their part however it
depends what you have in writing as they should have confirmed their instructions.

If i was in your situation i would write to the agent listing where they have not carried out there instructions, and if they are regulated ask to be entered into their clients complaints procedure. They are liable for the removal of the tenant as it is down to their negligence that the minor is in occupation in the first place.

It sounds like they are not going to be very good tenants especially with the older being paid cash
in hand.

However, one very quick albeit risky solution would be for the boyfriend to sign a new six month
tenancy agreement and the minor must not be put on this. This gets over the hurdle of being able to remove the tenants however they are there for an additional six months. It may be worth asking the boyfriend if he can provide a guarantor at which point you can get the rent guaranteed.

If both tenants are on the agreement then you can still serve notice providing one of them was 18+ at the signing of the agreement.

Why oh why do we hear the constant refrain from LA that the tenants were OK as far as the LA was concerned as they passed referencing!
When will LL learn that 'normal' referencing proves NOTHING!
The ONLY referencing that is of any use to a LL is RGI referencing or any referencing that is guaranteed to qualify for a RGI policy.
If a problem then occurs then a RGI claim mat be made.
'Normal' LA referencing does absolutely NOTHING for the LL.
The LA denies any responsibility, hiding behind their referencing.
The LL is then left with the problem of dealing with the wrongun tenant.
If RGI was in place the LL could leave the problem for the RGI company.
Why anyone takes a blind bit of notice of ANY LA referencing that doesn't guarantee qualification for RGI policies I shall NEVER know!
If a tenant fails to qualify for RGI at least the LL will know and then it is up to the LL to take the risk of taking on such a tenant.
Appreciating that it appears the tenant passed the criteria for RGI....................................................................HOW!?..........................Isn't it scandalous that the LA did not obtain the RGI policy on behalf of the LL.
Talk about a completely fraudulent and incompetent LA!
The more stories you hear about these incompetent LA the more I consider a pressing need for LA to be regulated; like Estate Agents.
There is no redress against these idiot LA.
Very few LA are compliant with all the good practices that are espoused for the industry.
We need regulated LA NOW.

Further to this we had a national letting agency let us down big time by failing to reference a tenant properly. This LA was (and still is) regulated by the various publicised bodies. The tenant defaulted leaving us out of pocket by a lot of money. Needless to say we "opted out" of our agreement with this agent and we now stipulate exactly what criteria is needed in respect of referencing checks with our current agent, who by the way, is a very good independent and does not belong to any of the regulatory bodies.
In terms of the agent who has let Marie down, I would say what you have described is bordering on criminal deception if you have paid money for a service to be carried out, which quite clearly hasn't on various issues.
I would get some legal advice regarding the agent for starters. This should include where you stand in terms of possible eviction procedures and also how to deal with the rogue agent.
As far as the tenant is concerned I would be totally upfront with him and fully explain what has happened. Was a deposit taken from him and what happened to that?
He, and his girlfriend, need to know exactly where they stand as the onus is on the Landlord to comply with most things concerning letting a property.
It sounds as though you have two choices; i.e. to start a new tenancy agreement from scratch or to politely ask him to vacate within a month if he cannot nominate a suitable guarantor.
Bear in mind that if he does agree to leave but fails to pay any rent that is due any rent guarantee insurance normally has a months worth of rent as a policy excess so you would be out of pocket anyway.
Any loses due to all of this then should be pursued from the original agent, either by means of a compensation claim when they are prosecuted in a criminal court, or by means of a small claims court action.
In my opinion it is definitely worth speaking to other local landlords in your area regarding which agents they recommend, or not, as more often is the case. I am very open minded about who the good and the bad agents are in my area and they fall in both camps as regards to whether they are under the scope of the regulatory bodies or not that are supposed to be there to protect us.

Once the tenant attains majority the problem disappears, they don't have to sign or do anything new the tenancy becomes enforceable.

The technique used to be to have a parent etc named as tenant with the under age occupier as joint tenant but Chris is correct and the Landlord in effect becomes the tenant's Trustee if the minor is the only named tenant.

In 20+ years practice provided the tenant is over 17 and not 16 I have never seen an actual problem with this. As IO say the whole key is them attaining majority then the problem is as if it never existed originally. The fact they entered into the contract uner 18 doesn't matter as they continue to benefit from it over 18.